Saturday, March 28, 2009

Worms in the Rain

Update (2013): I no longer squish dying worms because I fear doing so may cause more harm than if they died on their own. I do, however, try to move them off the pavement onto the grass so that other pedestrians won't inadvertently half-crush them.


It rained last night, and this morning, I was not surprised to see a number of earthworms strewn across a stone walking path. While a few of the worms appeared healthy enough to return safely to the soil, most were clearly either dead or sufficiently incapacitated that they would die within a few hours.

The sight is truly painful. When I'm not in a hurry, I feel obligated to stop and completely squish those worms that appear to be suffering but not yet dead. I make sure to slide my foot along the pavement so that the guts of the worm are stretched out, ensuring a quick and certain death. This is, I think, what I would most want someone to do to me if I were going to be transformed into a worm in such a situation. (It's the opposite approach, I assume, from what a Buddhist or Jain would do, which seems to me unfortunate given their supposed concern for all creatures. Sometimes reverence for life ends up causing more suffering.)

The task of squishing worms feels overwhelming, because there is a practically unlimited supply of nearby places I could go where I could find dying worms on pavement. It would probably not be optimal for me to spend my life seeking out worms so that I could put them out of their misery. But this is not because the expected reduction in suffering due to stepping on worms is small: Indeed, if we give worms, say, a 1/3 chance of being able to feel pain, and if only 1/3 of the worms I step on are not yet dead or unconscious, then in the five minutes it takes me to step on 25 of them, I will have averted roughly three expected experiences of slow, lingering death. Rather, the reason it probably is not cost-effective to spend my life on this task is that the stakes in other domains are so much higher: The amounts of suffering in nature as a whole are vastly higher, "beyond all decent contemplation."

In theory, it would be optimal for me to bypass the worms on the sidewalk so that I could have an extra few minutes to do more abstract work that has far higher expected returns. The reason I don't do so, apart from feelings of direct pity, is somewhat selfish: Thinking about how much I ought to be getting done in the five minutes I save is stressful and overwhelming. It's hard to go through life with the mindset that every five minutes you waste on trivialities amounts to (far) more than three expected worms suffering while they die helplessly. And yet this is true. The best excuse I can give is that humans are not built to handle emotional burdens on this scale.

By the way, if readers have suggestions on the worms-in-the-rain situation, I would be glad to hear them. As far as I can tell, the worms come out to escape drowning, though they may also use the moisture as a chance to mate. In either case, though, it's clear that many of the worms on the pavement are in no position to return back to the soil, as is demonstrated by their shriveled-up remains the following day. It's not obvious that the rain or pavement themselves are to blame, because, as Charles Darwin suggested, it may be that many of these worms "were already sick, and that their deaths were merely hastened by the ground being flooded." If that is the case, then worms in the rain represent merely a glimpse of the vast amounts of sickness and death that occur all the time among animals in the wild.

Note: Professor Jeffrey Lockwood wrote a nice reply to this blog post, which appears as the third comment below.


  1. I think your experience is quite common. The sight of dying worms troubled me when I was a child, and it still does. I've always returned them to the soil, though I'm not sure why.

    You could get a bucket of soil and place a couple of rescued worms in it to see how they fare after a couple of days. It could be that they're simply disoriented following the rain.

    Earthworms can live several years. I don't know if such lives are worth living, and there are good reasons to wonder whether the question is even meaningful. We don't know, though the maybe logic is, to me, unsettling enough.

    1. Yeah, I will release as many as possible but a few require my attention. I put them in a container with damp soil, grass, and leaves. Most that come into my care have been dried, and/or have been injured. I release them ASAP, however.

  2. You could get a bucket of soil and place a couple of rescued worms in it to see how they fare after a couple of days.

    That's an interesting experiment; I wonder if anyone has tried it. Of course, I would guess that professional helminthologists already know the answer and more.

  3. Professor Jeffrey Lockwood, an entomologist and philosopher, wrote to me with this reply on the above post:

    "You raise some interesting and valid concerns in your blog. In fact, I have a meditation in A Guest of the World (Skinner House, 2006) that also involves worms, sidewalks and rain (I’ve appended it below). I’d concur that it is ethically sound to kill a partially crushed worm (there is even some biochemical evidence that worms can suffer, as they possess serotonin and endorphins). They writhe and appear to exhibit behaviors that a compassionate and reasonable person would justifiably conclude are evidence of suffering (the issue being—if you are wrong and the worms aren’t suffering, then nothing has been lost by your action, other than a moment of time and the angst of mistaken empathy, but if you are right, then those who don’t take a second to act compassionately lose a great deal as does the worm). My sense is that it takes a rather long time for a partially crushed worm to die, as its physiology and anatomy are such that death would not follow nearly as quickly as it would for a mammal with a more complex and concentrated set of vital organs. As to death by drowning, my bit of digging around suggests that worms won’t drown during a rain (the acquire oxygen by diffusion across their bodies)—they are likely coming out during rain because this represents an opportunity for aboveground mating (copulation in an underground burrow is apparently no easy task, so the usually mate at night when the humidity is high; a rain provides a daytime opportunity)."

    Below is his piece, "Happiness is a Rescued Worm":

    "We wish to be happy. Likewise, we hope to have food when we are hungry. We do not merely wish for fullness: We eat. However, we often pine for happiness without doing something about becoming joyful. This is often because we don’t know what will make us happy. The sources of our unhappiness seem too diverse for simple remedies – friendless days, dreary jobs, uncertain finances. There would seem to be no single path to happiness. But every journey begins with a first step, and the initial stride is shared by many paths.

    "So what is this first step? The simplest acts of warmth nudge us toward joy. Stroking the family cat can create this momentum for me, as her purring dispels the dark clouds of angst. On rainy mornings, I often scoop befuddled earthworms from the busy sidewalk and plunk them back into the lawn. While cold-blooded creatures would seem odd candidates for warmth, their prevalence and vulnerability provide us with rich opportunities for affection.

    "When J.B.S. Haldane was asked what could be learned about God from the study of His creations, the famous British scientist replied that, in light of biological diversity, the Almighty had “an inordinate fondness for beetles.” Whatever the Creator’s affections, tiny creatures provide us with abundant chances to tend to the vulnerable. We can scoop a spider rather than crushing her or shoo a fly rather than swatting him.

    "There are, of course, more conventional opportunities to extend a moment’s tenderness in the course of a day: touch a friend, wave to a neighbor, or smile at a sales clerk. When I find myself hungering for happiness, offering a kind word to a co-worker is most assuredly a step in the right direction. But then, so is stepping over a sidewalk ant."

    1. I have grown to love worms so much that I can't walk over a healthy worm without picking it up and putting it where I think it wants to be. I have saved thousands of worms over the years. I have also, accidentally killed a few for various reasons. I feel I have done the a good thing even if it means coming home soaking wet from rain. I also pick up worms that are still moving but don't look like they are going to survive. The UV rays from the sun, and also cold wind are deadly to them. So I got some plain old goldfish. When I think I worm will die, I rinse it off and the fish get fed. That's the best solution I have so far. Worms are nothing but beneficial to all.

  4. As a small child, I too used to rescue earthworms. Then a moral dilemma arose. I agonized over whether to clap my hands to scare off a hungry blackbird who had snatched a worm.
    Now somewhat older, I still believe that members of other phyla matter. But I think we should prioritize the suffering of creatures with central nervous systems.
    This isn't just because I happen to have a CNS and earthworms don't. It's because there are substantive grounds for believing that invertebrates don't suffer as much as vertebrates. Thus a locust may carry on eating while being devoured by a mantis. This doesn't show that no pain is involved in insect predation. On the contrary. I think it's quite likely that nerve ganglia in the hindquarters of the locust register sharp pain. But there is no "unitary experiential field" that experiences agony in the way that our mind/brain would experience agony if our bodily extremities were being eaten. Indeed compare the hundreds of millions of nerve cells in the enteric nervous system of the human gut - a far larger nerve net than the nervous system of insects. Maybe its individual nerve cells experience rudimentary sensations; but there is no unitary experiential field. So we wouldn't judge that the enteric nervous system had independent moral status.

    Eventually, I think we can and should use nanotech and biotechnology to abolish invertebrate pain. But IMO its abolition can't yet be our main focus of moral concern.

  5. Thanks for the comments, Dave. Your point about mantises is a good one -- I think that is one of the better arguments against lower-invertebrate pain. On the other hand, to the extent that we use behavior as an indication, we would tend to conclude that worms do feel pain. When injured, they behave much more like you or I would than they do like a mantis being eaten or like our gut (which doesn't need to escape prey and so has little use for a "unitary experiential field").

    I'm not persuaded either way. Therefore, I agree worms deserve less weight than birds; on the other hand, being eaten is far more painful than going hungry, and a bird eats lots of worms in its lifetime....

  6. All that having been said, it may be overstating the case to say that all the worms one sees following rain are in fact MATING. Vulnerable to dehydration as they are, worms normally find the surface hospitable only at night — that's why they're called nightcrawlers. The one exception during the daytime is when the ground is soaked after a heavy rain. Both worms secrete mucus, covering each other with a 'slime tube' … Sperm are released and carried in grooves, now formed into tubes by the adjoining slime-covered worm, to the sperm receptacles of the partner. The worms then separate. Later [each worm] secretes a mucous ring, which slides forward over the worm's body, gathering several eggs from the oviducts and sperm from the receptacles as it does. Fertilization takes place within the mucous ring, which slips off the front of the worm, closing at both ends to form a capsule.

    Some get lost and dry out. But if you pick up any, at least put them together to sort out the 'love connection'.

  7. Hello Brian, hello all

    thank you for taking care of the worms and sharing this experience with us. I have been a worm farmer for many years now and love my worms

    The reason for worms leaving their burrows or their worm bins in wet weather is still not solved without the shadow of a doubt!

    We have narrowed it down to 3 probable reasons.

    1. worms migrate in wet weather because of fear of drowning. Worms breath through their skin and although being able to stay submerged in water for long times will suffocate if the water doesn't hold any oxygen anymore.

    2. Some worm farmers believe that the worms want to make use of the wet weather to leave their burrows and look for new mates to breed with.

    3. The last theory is the suspicion that worms dislike the noise and the vibrations that the rain drops make and feel the urge to get away from them. These vibrations might be similar to those that a digging mole makes when it is moving through the soil. Moles live almost exclusively of earthworms and they will flee as fast as they can if they hear one approaching. People that into worm grunting make use of exactly that fear.

    Whichever one of the theories is the right one is still a topic of discussion but it's a fact that worms and as such mostly adult worms migrate often at night during wet weather.

    On the topic of reducing the suffering of the worms. They usually wiggle wildly when exposed to the sun and when their skin gets covered with sand and or soil particles.

    The sun will dry them out quickly which will lead to them dying within a few minutes of exposure.

    The sand covering their skin will prevent them from breathing (they breath through their skin) and will suffocate them as well in a short period of time.

    If you see worms wiggling on the pavement there is still a good chance that they can be saved by either pouring some water over them or placing them in a bucket of water for a short while. This will protect them against the sun and will wash off anything covering their bodies.

    I know it might be time consuming but a quick way to pick up worms is with a soft hand broom and a dustpan.

    So a small bucket with water, a hand broom and a dust pan might save many worms :-)!

    If they are beyond help your method of squashing them might be the way to go.

    Kind regards and thank you for sharing and caring

    1. Thank you- informative and concise!

  8. Lately while walking my dog whenever I find a lost or disoriented worm on the sidewalk, pick it up and place them on moist soil. We all must do whatever it takes to prevent suffering.

  9. Thank you, Stephan and Anonymous! It's great that you also care so much about worms. :)

    Stephan, I didn't know that sand could suffocate worms -- that's good to know. Your suggestion about a broom and dust pan for efficiency is great.

    As far as whether it's humane for the worms to be squished, or whether they'd rather die on their own, I'm now unsure of the answer. I actually err on the side of just leaving them, worrying that the pain of shredding their bodies might be worse than dying of another cause (dehydration, suffocation, organ failure, or whatever).

    There's also an interesting question about whether helping worms now means they have children that then suffer more. Without knowing more it seems okay to rescue worms and leave it at that, but I think exploring the ecological nuances of these questions would be important. :)

  10. I save worms. I'm thriled i'm not the only one.

  11. I think earth worms contribute positively in most ecosystems by enriching the soil. I think that developed areas are probably more dangerous to worms than their natural ecosystems because there is less soil and fewer leaves to hide under.

    I can think of two ways to help them out:

    1. Create a roomba-like robot that could sweep them up, rinse them off, and drop them off in a safe place with other worms

    2. A more permanent solution is to create safe places at the edge of pavement or concrete. It just needs to be a barrier that discourages them from leaving the grass and venturing onto the pavement, and allows them to get out of the water to avoid drowning. Idk how someone could gauge the effectiveness of this though.

  12. Hey wannabe steamroller,

    don't squish and kill the earthworms.

    i give you benefit of doubt, as you might have acted wrongly, as your knowledge might be lacking.

    the main yardstick is- would you do it to yourself. forget your hypothetical fictional situation examples where you are transformed into earthworm etc

    consider something more likely for many of us in our life time. would you kill yourself if you were in similar situation, where premature death was foregone conclusion, for example, had a terminal illness and had a few months to live.

    didn't think so.

    always remember. each life has equal value. this is complete truth.

    you may stupidly think earthworms serve no purpose, but the same could be said about you or me, do you think we serve some special purpose in this nature. no matter if our grand inflated ego thinks otherwise, we do not.

    now that you know the truth, how about making some amends. next time, pick the earthworms and place them in comfort of a lawn, just like a sick patient chooses a hospice rather than get trampled under a steamroller.

    be well.

  13. I often see worms all over my patio during really rainy times and if I don't pick them up they all drown and dry up sticking to my concrete. So I just pick up as many as I can several times during the rainy days and put them in some pots with soil. Do you think it might make a difference if it's soil or dirt? I knew they dried up from the dirt but didn't know it was suffocating them glad to know that now. I've picked them up when seeing them dirty and dry and just put them back in the grass but washing them off sounds better.

  14. Hi April,

    It's great you do that! I don't know about the soil vs. dirt question, but presumably either is better than leaving them to drown. I'm not sure washing them matters very much, though if they're very dry, I suppose they might benefit from the moisture. If the worms could speak, they would say "Thank you". :)


    Even if a worm is half squished, it has a chance of regenerating its body. It seems like sometimes "compassionate" killing might actually be killing when the worm may have lived (and regenerated) if it had had a chance.

    Also, how do you know a worm would rather die quickly with a crushing heel versus slowly? Personally, I differ from you. I'd prefer a "slow" lingering me a chance to prepares, says I. How do you know a worm's perception of death is the same as yours?

  16. Thanks, Anonymous. :)

    Usually the worms I see look near death. It's not as though they've only been chopped in half cleanly; usually they're either partly drowned or crushed to a significant degree or drying out.

    I'm pretty sure a worm doesn't have a concept of life and death, since understanding such things requires complex cognitive machinery. Mostly I'd guess the worm is just in pain and struggling in various ways.

    That said, as the current top paragraph of this post notes, I usually don't currently squish dying worms because doing so may be painful unless squishing is complete and instantaneous.

  17. I find the post above sinister and a bit demented. I recently listen to a small part of a Neil Young documentary where he talks about his childhood. He mentions how in his hometown he used to use firecrackers to torment and kill turtles. He referenced is as if "everyone kid does those sort of things". He joked about it as he is such as strong environmentalist today.

    The truth is every kid does not do those things. I think there are lovers and appreciators of nature, and those who are self-centered and harmful towards it. And all sorts in between who don't give it a second thought. As kids, which you are or were says something significant about your underlying character.

    I once picked an injured Goose off a major highway, and took it to a local bird rehab center. Another time, chased a lost ground hog off the road and back into the woods before a car got it. If my wife spots a spider in the house, I grab a plastic cup, scoop it up and take it outside. And yes, very often, I go out in the rain and pick up worms who might be drowning and place them back into dry soil under the overhang of our house.

    It's a weird thing we as a society, differentiate life based on looks or proposed ability to feel. We love puppies and kittens, maybe like the Bluejay or Robin but not the crow, and our feelings lessen when we move to reptiles, spider and insects. And worms.

    All life is beautiful, serves a purposes and if it can be saved why not. Why smash the spider on the wall just because us as big humans are a little too scared. I'm not saying you need to avoid every ant in your path, but you don't need to go out of your way either to kill them. Same with worms. Some will drown, some will live. You don't need to save them, but you don't need to kill the ones you supposedly think are in bad straights. You're just enjoying some bizarre act of killing. Don't fool yourself into believing being the Dr. Kevorkian of worms you're doing them any service. Let nature take its course.

    Spiders when saved help control our insect population. (Though we all know the superstition "if you kill a spider it will rain, and then you know what, the worms are screwed too!")

    Worms help aerate and fertilize the soil, and help supply the bird population with food.

    When I see a worm struggling in the rain, returning it to the soil is returning it home. It's like returning a stray bird to its nest or a lost cat to its owner. When I see a worm on the path and 'save it', I feel good. Sure there are plenty of worms out there, but just knowing I might have saved one of God's creatures for a bit longer to let the course of nature for it continue is a beautiful thing. Saving 30 even better. Professor Lockwood's post of "Happiness is a Rescued Worm" has some wonderful thoughts in it. Any kindness towards life is a way to share tenderness, receive joy and exhibit the kind of person you are - and should be.

    1. Don't put spiders outside! They will die of the cold! All the best :)

    2. "You're just enjoying some bizarre act of killing. Don't fool yourself into believing being the Dr. Kevorkian of worms you're doing them any service. Let nature take its course."

      With all due respect, I think you kind of missed the point of the post. He doesn't do it because he takes pleasure in killing the worms, but simply because he feels that the worms are better off dying quickly than agonizing for hours. Or that's what he felt at the time, anyway -- the update, made prior to your comment, explains that this may no longer be the case.

      It's the same reason why a pet dog who is very old and afflicted with a terminal illness will be euthanized before the pain becomes intolerable. No one likes to do this but it is, as far as we can tell, the best thing to do for the dog. Nowadays even humans who are terminally ill can request this service if they want to live out their final days with a clear head and as little pain as possible, and many of them do make use of it.

      The problem with letting nature take its course is that nature does not have the interests of any creature at heart and fosters enormous amounts of unnecessary suffering. It is perfectly natural, for example, for a young dog to lie crippled on the ground after an attack by some bigger animal, suffering uselessly for many hours before finally dying. But I think anyone with empathy can recognize how abhorrent such a situation is, and would want to save the dog or at the very least let it expire quickly. If a human were in that situation, I can almost guarantee that they would get help and no one would even think of 'letting nature take its course' by letting them become food for scavengers. It only seems fair to extend at least some of this concern to species that are further away from us.

      Now, as mentioned in the post update, it's questionable whether this is truly a good solution in all instances and it may be safer to give the creatures the benefit of the doubt. I still think that there are situations where a quick and complete squashing (emphasis on 'quick and complete') can be the best thing to do, though.

      For example, I sometimes find snails with broken shells when I'm walking around outside. Some of them clearly have a chance to pull through so I collect and keep them if I can (I have a small snail colony at home) or otherwise place them in a moist shady area so they can try to recover. Sometimes, though, it is painfully obvious that they cannot make it -- whole areas of the shell are missing, the body is almost completely exposed, the snail has visible lethal injuries, etc. In one such case, with a gravely injured and almost shell-less juvenile snail, I felt an obligation to end its life quickly rather than let it struggle in that awful state, completely exposed and vulnerable (and quite likely suffering a lot, in whatever way a snail can). I assure you that I took no pleasure in doing it and would have rather not had to do it at all; I even cried afterwards.

  18. how to avoid worms without killing when they surface out at floors outside house ..actually they pore out through drains' openings...even sometime at washrooms

  19. Hi Nasty Nitin,

    I'm not sure what to do about that problem. I guess you can watch your steps carefully. Maybe you can figure out where the worms come through in order to block the holes or something (as long as doing so wouldn't trap the worms)? Feel free to say more about your situation or ask the question on this group:

  20. Hello. I am an avid rescuer of struggling worms. I never thought I'd find anyone else who cared so much! I do the same with snails and anything else really. I pick up the worm, try to dig a bit in some nearby soil, and place him in there so he can decide if he likes it. Today there was a worm that seemed to be struggling wildly in the grass and it was terrible. He was still very moist though so I'm not sure what was going on. I did what I normally do but I after placed him in the soil, I saw he had a few bright yellow oblong spots on him. It kind of scared me since I touched him with my bare hands. That lead me to searching for what these spots might be, which led me to this blog.

    Sometimes I struggle with re-homing snails and worms who seem like they will die if I don't. I wonder "What makes me think I know where they're going? What if they went all this way and I'm just setting them back? Who am I to be disruptive?" For these reasons, I always try to send them in the direction they were originally headed and I only move them off of the sidewalk or out of obvious harm's way. Thanks for the discussion. Sometimes caring so much is hard. If everything wasn't so wasteful, maybe it wouldn't feel so bad to see them like that. I hate it.

    1. Hi Sarah :) Thanks for caring so much about this!

      Moving worms/snails out of harm's way is great. I assume it's better not to bury snails.

      I'm not an expert, but I assume it's ok to move worms, snails, etc. by some distance to rescue them. I don't know if they have definite homes that they're trying to reach. Apparently earthworms use taste and smell to navigate.

      I don't know what the spots were... Maybe some kind of infection / parasite / etc.

      > "Sometimes caring so much is hard."

      Yes. :) But its worth it to know you're doing the right thing.

  21. Hi,

    It is great to know my family and I are not the only people to carry out worm rescue:)

    We aslo revive flagging bees with sugar water.

    All life has value and it lovely to know there are some great people out there!

    1. Thanks, Florida. :) It's great that you and your family care for other creatures as well.

  22. I am so happy to have found this post. I really thought I was the only one who cared this much. :)

  23. So please I found this blog. Just saved a worm who was drying on on edge of patio, placed him in shady damp place in garden to give him a chance of another day :) I save any struggling animal or insect, and can't bear to see anything suffering.
    It's lovely that others are also compassionate. I only wish the whole of the human race shared our empathy. The world would be a beautiful place.
    It saddens me how cruel many people are. I guess most people would find us eccentric, but I'm happy that I've been kind to all nature while I'm on this planet.

  24. My young son laughs at me every time I'm out there after a rain scooping earthworms up off the sidewalk/concrete and putting them back into the dirt. I catch and release spiders, too. I try to use it as a teaching moment about compassion and empathy for all living things. Glad to see I'm not the only one who cares :)

  25. I live in Southern California, and we just had a huge rainstorm. I went for my morning walk and just spent an hour and a half saving about 500 earthworms in the gutter between the sidewalk and the street. I threw them back up the bank in the dense weeds. I always save worms when I see them, but I have never seen this many that needed saving.

  26. Wonder how many don't make it to the concrete? Does that mean there are thousands of dead worms in my back yard after a hefty rain? There seems to be no shortage of them. BTW my dog has a picnic on the patio when this happens. They are usually like a soft piece of jerky.

    1. Hello!I don't think the rain kills the worms. it only gives them a chance to surface safely in hopes of mating or whatever other reasons without drying out. they should be fine in soaked soil

  27. A very interesting discussion. Thank you!

  28. Considering the worms aren't drowning - they breath through their skin and come out when it rains as it allows them to move overground, you are in fact killing them needlessly. "Q. Why do worms come onto driveways and sidewalks when it rains?

    A. Dr. Dennis Linden, Cindy Hale, and other worm experts say that worms do NOT surface to avoid drowning. In fact, they come to the surface during rains (especially in the spring) so they can move overland. The temporarily wet conditions give worms a chance to move safely to new places. Since worms breathe through their skin, the skin must stay wet in order for the oxygen to pass through it. After rain or during high humidity are safe times for worms to move around without dehydrating. It is true that, without oxygen, worms will suffocate. But earthworms can survive for several weeks under water, providing there is sufficient oxygen in the water to support them."

  29. much appreciated article. i wanted to know how to help worms./ thanks

  30. I was searching for why worms surface after rain & found this thread. It's been raining for a few days & there are so many worms all over the pavement on the school run - I could never squish them - I have a very skinny twig - my 'worm stick' - & my son & I scoop up as many as we possibly can & put them safely in the nearest garden on the soil. I wasn't sure if we were doing right but I couldn't leave them to get trampled on or dry out. Every creature matters!