Why is my Snail Out of its Shell? Is it Dying?

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Unfortunately, there were times when I found my snail out of its shell. At first, I took it as a natural process most snails go through. However, over the years, I learned why snails get out of their shells. To my disappointment, it wasn’t an innocent action.

Snails typically get out of their shell when they are dying. Naturally, the shell is attached to the snail via its mantle. However, a dying snail shrinks, and its mantle decomposes, forcing it to leave its shell. That usually happens due to inappropriate water conditions and violent predators.

As we move forward, I will show you what to do with a snail that has just left its shell. Since they are unlikely to survive, it usually involves euthanasia. I will also show you what kit I use to monitor my aquarium’s parameters and prevent this issue from reoccurring.

Why did my Snail Leave its Shell?

Snails can come out of their shells for any number of reasons. They will emerge to look for food, to mate with other snails, to lay eggs, and so much more.[1] But there is a big difference between a snail coming out of its shell and the snail leaving its shell behind.

As I will elaborate later on, a snail cannot live without its shell. More to the point, a snail would never abandon its shell. If your snail is out of its shell, one of the following might be the cause:

1. Your Snail is Dying 

Death can cause a snail to leave its shell. The shell grows with the snail. As such, you don’t have to worry about a shell being too big or too small for the snail. However, when a snail dies, it decomposes. This causes the creature to shrink in size until it falls out of the shell entirely.[2]

If your snail is out of its shell and it is immobile, it is most likely dead. You can test this theory by stimulating the creature. Touch it. Add food to the tank. Turn the lights on (some species are nocturnal). If it refuses to respond to all these stimuli, you can assume that it is dead.

The most common reason for a dying snail is inappropriate water conditions. That includes pH, temperature, ammonia, nitrates, and nitrites. That is why I now use the API Aquarium Test Kit (link to Amazon). That bundle allows me to monitor these essential parameters accurately. Within five minutes, I know if something went wrong.

2. The Snail Got Hit by Predators

Creatures like Dwarf Pufferfish can suck a snail out of its shell.[3] And they are not the only ones. Loaches do the same thing. You may never know what happened to your snail in such a situation because the only clue left behind is an empty shell.

3. Mantle Damage

Some aquarists have seen their snails moving in the tank with the shell trailing behind them and barely holding on. This can happen in situations where the mantle and the shell have separated. The mantle can tear or collapse due to damage (from a fall, a fight, etc.). Other reasons are a disease or infection that caused the connection between the mantle and the shell to degrade.[4]

Do Snails Come Out of Their Shells When They Die?

Snails come out of their shells when they die since the mantle, an organ connecting them to the shell, dissolves when their general state deteriorates. However, some snails will retreat into their shells before dying. Then, the typical sign of a dying snail would be the unpleasant odor it releases.

The decomposition process will also cause the ammonia concentration in the water to spike.  After a while, as its carcass rots, the snail will shrink in size, proving once and for all that it is definitely dead. In some cases, the snail will decompose from inside the shell until the carcass disappears completely.

In other cases, the snail will fall out of its shell. It may start by hanging out of the shell, but eventually, it will fall out. Some people will encourage you to check on the snail before concluding that it is dead. But if the snail has separated from its shell, it doesn’t matter whether it is alive or dead. Even if it is alive, the creature will eventually die. This is a given.

Can a Snail Survive Without its Shell?

A snail cannot survive without its shell. A lot of snails die when their shells break. This is because the punctures cause the snail’s body and organs, which the shell protects, to dry out. However, punctures and cracks are not always a death sentence.

You may either patch the holes or nurse the snail until it heals; snails can repair minor damage.[5] But if the shell is completely gone, the snail has no chance of surviving. You can prolong its life by keeping it in humid conditions. But that will only extend its suffering. Snails cannot live without their shells.

Why do Aquarium Snails Need a Shell?

Snails can stick portions of their bodies out of their shells. They cannot separate their bodies entirely from the shell. If you are new to snails, this is what you need to understand about their shells:

1. Development

Some people treat shells like a house that a snail can enter and leave at will, but that isn’t the case. Snails are born with their shells. They are small and soft at the start. But they harden over time, becoming a robust and defensive tool that grows to match the snail’s size.

A snail’s shell is as important as any other organ. A human being cannot ditch their fingernails at a moment’s notice. Well, snails are the same.[6] They cannot simply walk out of their shells.

2. Purpose

The shell plays a defensive role. It protects the snail from predators. If you have snails, you have probably noticed that they always retreat into their shells whenever they feel threatened. However, predators are not the snail’s biggest concern.

The shell is also responsible for keeping the snail’s organs safe. This is on top of preventing the creature from drying out. Snails whose shells break will dry out and die unless an aquarist takes immediate steps to patch the hole.

If cracks and punctures in the shell are such a significant threat to a snail’s existence, you can imagine what would happen if the snail was forced to live without a shell. The results would be far worse.

3. Accidents

A snail cannot slip out of its shell by accident. As was noted above, a shell isn’t a house that the snail can enter and leave at will. The snail is connected to the shell via a layer called the mantle.[7] 

The mantle allows the snail to maintain its shape within the shell. The snail cannot choose to detach itself from the shell simply because it wants to take a stroll without the weight.

What to do if my Snail Got Out of its Shell?

If you have any attachment to your snail, you won’t like the answer. Snails cannot survive outside their shells. A snail that is separated from its shell will die. Nevertheless, the time it takes the snail to die will vary.

Some take hours. Others take days. Regardless of the situation, a snail that has left its shell is guaranteed a slow and painful death. The only thing you can do for a snail in such a situation is to kill it quickly.

Some people argue that you can save the snail by placing it in a damp environment and keeping it moist by regularly spraying it with water. The objective, as you may have guessed, is to prevent it from drying out.

But experienced aquarists will tell you that this strategy only serves to prolong the snail’s suffering. Your best option is to give it a quick death. The method used will depend on the tools you have on hand:

1. Crushing the Snail 

This is the most popular means of euthanizing snails. People take this route because it is convenient and straightforward. All you need is a heavy object. Strike the snail as hard as you can. One blow should be enough. Snails have soft bodies.

Healthy snails are a little tricky because they have a shell. You run the risk of failing to crush them instantly on your first attempt. But a snail outside its shell doesn’t present the same challenge. The method guarantees the snail a quick death.

If you don’t want to make a mess, wrap the snail in a towel or newspapers beforehand. Admittedly, some people think that this approach is far too brutal. They don’t have the stomach for it.

2. Putting the Snail in Salt

 Snails don’t like salt. This is common knowledge. Therefore, few weapons are as effective as a salt solution if you want to kill a snail. Get a small container and fill it with boiling water. Add copious amounts of salt. Shake the container until the salt dissolves. 

Then, place the snail in the solution. If the solution is adequately saturated with salt, it should kill the snail in a few minutes. Once the snail dies, you can throw it away.

3. Using Beer

This might come as a surprise to some aquarists. You can use beer to euthanize snails. Scientists have found that a solution of 5 percent ethyl alcohol can sedate a snail to the point where it becomes unresponsive.[8] In this state, they do not feel pain. Of course, this is simply the first step.

If you sedate a snail using alcohol, the effect will wear off within the hour. You have to kill the snail before this happens. The method you use doesn’t matter. The snail cannot feel pain. Regardless of how you choose to kill it, the snail’s death will be humane.

4. Using a Freezer 

Place the snail in a plastic bag. Then, put the plastic bag in a freezer and wait a few hours. All of this assumes that you care about the well-being of the snail. Some aquarists are not interested in giving their snails a painless death. 

All the same, you have to remove the snail from the aquarium. If it dies without your knowledge, the currents could sweep its carcass into a corner where you are less likely to find it. It will decompose, ruining the chemistry of your aquarium in the process.

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If your aquarium snail left its shell, it would probably not survive. Your next best step is to take it out of the water and perform euthanasia. Otherwise, the snail will rot and ruin the water chemistry (causing ammonia spikes in particular).

As a rule of thumb, aquarium snails shouldn’t leave their shell. Their mantle ensures that they remain connected to their shell even when they move across the tank. If your snail is no longer inside its shell, check the water parameters and see if they are suitable.


  1. https://animals.mom.com/why-snails-come-out-of-their-shells-5090596.html
  2. https://www.tropicalfishcareguides.com/aquarium-fish/how-to-tell-if-a-snail-is-dead/
  3. https://aquarium-fish-plants.com/keeping-pea-puffer-fish-in-the-aquarium-this-is-how-it-works
  4. https://www.petsnails.co.uk/problems/mantle-collapse.html
  5. http://everythingnothuman.com/animals/can-snails-repair-their-broken-shells/
  6. http://www.thesnailwrangler.com/education/frequently-asked-questions/
  7. https://www.madaboutsnailbooks.com/slithering-facts/
  8. https://www.sciencedaily.com/releases/2016/10/161006092859.htm