Do snails sleep?

[snailbert]

Hi everyone,

I`m still very new to snailkeeping and just received 4 adult achatina fulica this monday. So far they seem to do fine, eat a lot and climb around in their tank.

However, this morning I woke up and discovered all 4 them with their heads partially retracted and they weren`t moving. After cleaning the tank and changing food/water I picked them up and dicovered that 3 of them had poop stuck under their head.

I removed the poop with a small spoon and put them back in the tank, shortly after they all became active again and started eating.

After that expierence, I wonder: do snails sleep? I already read many articles about snails, but I never spent any toughts on the topic sleep.

Cheers,
Snailbert

[coyote]

I've seen my snails motionless with their heads out, and if they are on the side of the tank their eyestalks are drooping down too. They seem to be in a sleep-like state. I don't know whether snails sleep the way people do, but I wouldn't be surprised if they go through a stage of something akin to sleep.

[ness]

Snails do rest, just as many creatures rest, though I wouldn't class it as sleep - not true sleep as we know it anyway.

Most animals require some resting periods in order to conserve energy needed to grow/maintain/repair their bodies, and will be inactive while they do this. For 'higher' animals this is when the animals sleep. For snails - well I think they just rest and become slow to respond during this time
As your snails get older and heavier you may even find a resting/sleeping snail loose it's grip and slide down the tank wall or even fall off the underneath of the tank lid!

[snailbert]

Hi guys,

thanks for the fast reply!

Is it also known if snails have cognitive abilities such as self-awareness?

[coyote]

That's a great question, and I don't think anyone really knows.

How would one go about testing a snail's self-awareness? That would be a challenge.

[snailbert]

Maybe snails have a very subtle way of communication (scent, slight movement or gestures) which hasn't been understood/discovered yet.

For one, I see behaviour like each snail having different food preferences as a fair chance that some sort of personality is present, but that's only my guess.


What would also be interesting to understand is what kind of "feel for time" a snail has and how they expierence the world surrounding them, but maybe we'll never know for sure.

[ness]

Apr 24, 2011 1:13:42 GMT snailbert said:

Hi guys,

thanks for the fast reply!

Is it also known if snails have cognitive abilities such as self-awareness?

It isn't certain, however it is known that snails have memory and are capable of learning, though on a simplified scale.
Some (maybe most?) species have a homing instinct which has been tested by several people incluing scientists, whereby a snail taken out of it's normal foraging range will head back to the place where it usually rests during the day. Snails have a great sense of smell, and is their main sense, which probably has something to do with their homing ability, but those testing the snails believe they possess memory too.

When you keep a group of snails together you may find that they exhibit preferences, in that some will huddle up with others when they rest and others usually go off on their own. Some will rest on the tank lid, others on the wall or under a fake plant etc. They appear to establish a resting place that they will use again and again. Yet others will just rest anywhere. Perhaps some respond to an instinct that tells them them to go to the same place each time, while others respond to where the best temperature is on any given day? I'm not sure and have never done any experiements to try to find out.
I once had a pair of snails that used to follow each other around, they were Archachatina marginata from the same litter, housed with other snails. It could be that they were responding to an instinct to be with the same species and that being litter-mates the smell of each other would have been the most familar to them.

Many snails will also mouth each other around the head and neck, and the recipient will be seen responding in a 'positive' manner by stretching itself out. Do they like the touch and why? Are they capable of feeling pleasure? Could it be that some snails do this before mating and therefore they respond well to gentle touch, even if it's by another species, and is purely an automatic response?

And yes as mentioned even litter/clutch-mates kept together can exhibit different tastes in food, but it may be due to having a slightly different way in which they process food smells, or maybe there is some kind of instinct whereby snails housed together go for different kinds of food so as to decrease the competition for any one particular food in their environment, and each snail will go for that particular food first each time? I don't know, it's interesting though. Tastes in food appear to be learned to a degree. Some snails raised on a particular diet are known to turn their noses up at new types of food, whereas others seem to eat anything. Some snails really are very fussy eaters!

I love to think of snails with personalities and even that they are curious at times (as they look that way when they stretch out their necks high and look around), but in reality I believe alot of it is due to automatic responses to the smells/chemicals/scents in their environment, and instinct.

[Hannah-Bird]

I posted the other day that all of the related babies had been sleeping together. I agree that a lot of it is instinctual, but a lot of it sure does look like a personality.

A couple of nights ago, I moved the biggest of the babies--Simon--into the adult tank. I was a little unsure about separating him from his siblings, but he seemed intrigued by the new environment. He circled the outer leaves of the plant a couple times, then settled down on the cuttle bone. When I checked on them the next morning, Arial and Sterling were on the plant and wall respectively, and Simon and Lenore were sleeping shell-to-shell in a corner! At first I panicked and thought there had been oedipal shenanigans, but there wasn't a love dart to be found, so I don't think that's what happened.

Lenore is Simon's mother. While I don't think either one of them is aware of that relationship (as far as I can tell) I did keep Lenore in with the babies for several weeks. She's the only one of the adults that Simon has been around extensively, so it seems to me that he remembered her smell and knew that it was a safe bet to stay with her. ... Maybe it sounds like kind of a stretch, but even that sub-level of Momma's Boy behavior seems pretty cool to me.

[freedomchaser24]

one of the questions seems to be here...what constitutes as a personality, as our own personalities developed purely out of instinct, becoming more complicated as we grow or evolve. i do believe snails experience pleasure, as pleasure is one of those instincts that helps drive an animals survival. maybe it is one of the most basic along with fear. though any pleasure they do feel, is probably only received by them in a simple way. saying that tho, snails have very simple eyes so i would imagine they make up for it with their other senses. their skin is probably much more sensitive than ours. and also, pleasure can clearly be seen when 2 animals are mating (excluding the female cat of course lol)

[Hannah-Bird]

What you were saying about their limited eyesight compared to strength in other senses reminds me: I recently read that snails have no sense of hearing. I've put a lot of mental stock into the idea that my snails hear me over the years, so that made me feel really silly.

Then I remembered something from when Lenore was a baby. I was keeping her (sorry, guys) in a mason jar back then, and I'd take her out every night to "play" on a damp paper towel with some fresh food. She liked the Beatles. I played all sorts of music while I was working and letting her stretch her proverbial legs, but she was always more active and more interested in her surroundings when I had the Beatles playing. I witnessed it frequently enough to think that it wasn't just a coincidence.

I wonder if snails have a form of hearing that scientists haven't been able to figure out. It crossed my mind that (while this is wildly unlikely and unprovable) maybe they have some sort of telepathic ability. This isn't to say that I think she was literally hearing the music through my head, but rather picking up on the emotions it caused in me, which was a purer form of happiness than some other music would evoke. We're getting into seriously metaphysical territory, but maybe that's even how they communicate. Human emotions are so much more complex than those of most other creatures, that maybe that's why we develop such strong bonds with our snails. Or maybe I'm just talking out my arse. I'm not sure. Lol.

I do realize that a lot of this is just plain silly, but I think it's worth thinking about. Anybody think it's worth discussing?

[snailbutler]

I think snails can sense vibrations caused by sound so I suppose it's possible that they can detect rhythm but it's fairly unlikely that they can detect melody. I can't imagine that The Beatles would sound quite so good if the only element you could sense was Ringo's drumming.

[coyote]

I suspect that a snail could feel the vibrations of the music in its body somehow. Maybe its foot feels a tickling sensation?

[crossless]

How snails could hear if they don't have auditory organ(s)? It's nice to watch when my snail notices me spraying terrarium. I think it starts to feel moist breeze round itself.

[ness]

I LOVE science, including theoretical science, and enjoy these sorts of discussions. Not only do I enjoy learning how things work (snails included) I also enjoy when new discoveries are made, especially when they are surprising. Sometimes we think we know something, or we think we can completely discount something, and someone discovers something that challenges the way we previously thought.

I wouldn't discount any metaphysical abilities in animals, I tend to think of myself as open-minded while skeptical, and I actually like being proved wrong at times. Really.

However I would have to say though that I have my doubts about metaphysical talents in snails. This is on the basis that I don't think they have any social or physical need to communicate on an emotional level. It would make evolutionary sense (assuming it's at all possible) if it would help them to find mates, food sources or warn of danger but I have never seen any behaviour that would make me think of this happening. I am thinking, for example, when I've been out snail collecting. Picking up snails as they are sliming around minding their own business seems rather startling to them, and as you would expect some of them retract quickly as they are picked up. I have never seen any surrounding un-touched snails react to this happening in any way so I am assuming they are not picking up on the reactions of the picked-up snails.

However, there has been a study on dogs where the scientists have given instructions to the owners to leave the house and come back at random times, varying the mode of transport. The dogs all started reacting by stopping what they were doing and waiting at the door when the owners made the decision to come home. I find this very interesting.

I do believe in connections between animals and people that science has yet to truely identify and define, but I have doubts about such connections in snails - to people or to other snails.

I agree with others that the snails reacting to music is likely to be sensing the vibrations. It is possible that some vibrations attract snails, such as those that feel like running water - where there's fresh running water there if often fresh food, damp air and damp soil - just right for snails. Then again perhaps they are more likely to use smell to find water? Perhaps the vibrations simply feel nice?

It is usually true that animals evolve to the extent best required for their survival. The brain of mammals and quite probably all animals is a fuel guzzler - i.e. it takes a large proportion of energy to 'run' the brain. For this reason none-essential senses (and senses take up alot of brain power) tend to be limited. some never really develop, others develop and then due to a change in circumstance are not needed so the sense devolves over many generations. Snails are not very energy efficient in the way they move, so the less energy expended on things such as extra senses the better. Snails need to be able to smell their environment and check out the health and sexual receptiveness of potential mates (again via smell). Much of their brain power (they don't technically have brains but ganglions - bundles of nerves that act like mini-brains) would be taken up by this vital sense, most other senses would be a waste of energy to them.

[crossless]

I think my tigersnail has homing instinct. I once changed order of snail tank so that food would be in right end of tank snail just went there eating some food and came back to other end. He rarely yet go to otherside of terrarium he just uses half of terrarium and it's always left side of terrarium. When he gets older maybe he spend more time in other end of tank too. He has always one spot where he sleeps even when conditions in terrarium are identical all corners of the tank.

Older the tiger gets little bit bigger changes his territory.

Fulicas were moving everywhere in tank in really young age already.

Nice to notice differences on behavior between different species.

[barnaclesnail]

May 7, 2011 19:12:13 GMT Hannah-Bird said:

I recently read that snails have no sense of hearing. I've put a lot of mental stock into the idea that my snails hear me over the years, so that made me feel really silly.

Then I remembered something from when Lenore was a baby. I was keeping her (sorry, guys) in a mason jar back then, and I'd take her out every night to "play" on a damp paper towel with some fresh food. She liked the Beatles. I played all sorts of music while I was working and letting her stretch her proverbial legs, but she was always more active and more interested in her surroundings when I had the Beatles playing. I witnessed it frequently enough to think that it wasn't just a coincidence.

I wonder if snails have a form of hearing that scientists haven't been able to figure out.

You couldn't convince me snails don't hear, even though I also recently read they cannot. They must have some, even if only crudely developed, auditory organs or sensory ability that allows them to hear - maybe like a sensitivity to vibrations or the way cats can taste with the Jacobson's organ, I think snails must have the auditory equivalent.

When I run the faucet, they crane their heads even if they're not in direct sight of the sink - they definitely recognize the sound and go looking for the source I've seen this behavior so many times I honestly didn't believe it at all when I read they're not capable of hearing.

[saki114]

snails rest, but dont necezsicarily "sleep".