Your snail likely crawled out of the tank to explore, find more food, lay eggs, escape poor water quality/tank mates, or because it's a natural "escape artist" species like a nerite; a lid is crucial to prevent falls, but checking water parameters (ammonia, nitrates, pH, GH, KH) and ensuring enough food are key solutions.
It can be due to water conditions, overcrowding or other factors but most of the time their is nothing wrong and they are just exploring. I just let mine do their thing. I do not have a lid on my tanks and have never had one not find their own way back to the tank.
Your snail may be looking for a place to lay a clutch of eggs, and they usually do that above the water line.
A stressed snail stays sealed for days and might smell bad when you gently sniff near the shell opening. Don't panic if your snail hasn't moved all day. Just give it time and check again in a few hours.
Aquarium Salt
Just as salt will harm snails or slugs on land, it will dehydrate snails underwater as well (and yes, even things underwater can be dehydrated!) For this method, use aquarium salt or kosher salt to make a solution of one cup per gallon of water.
Snails are extremely simple creatures so as long as they not hiding in their shells and eating, that should be enough to tell if they are healthy or not. Also, if their shell is cracked or melting, it's a sign of calcium deficiency so look out for that too.
Mystery snails can stay sleeping/hidden in their shell, for up to 3 days. Don't ever just assume they are dead. This is also breeding season, so if you happen to find a clutch of eggs, above the water line, you'll end up with babies. If you don't want them, they're easily removed and disposed of.
Ive seen survivors that were out of water for 5 days, It depends on the size and age of the snail. Larger snails last longer it seems. There ability to seal themselves up, breath air, and their slow metabolism from being in a hibernating-like state is what helps them survive.
Please be aware that if you pick up snails to move them to safer places, you could unintentionally cause them pain if it's not done properly. Ripping them away from the ground can cause the mantle to collapse — which can be fatal.
Both snails and slugs rely on moisture to survive. Their bodies dry out very quickly when they are active without moisture to support them. This is why they only become active when it rains or when you've recently watered your garden.
They are aquatic snails, but they can spend a long time out of water. Just make sure you have a lid and cover the openings so that he doesn't escape again.
Because of their size, one or two mystery snail can live in a 5-gallon aquarium or larger with a tight-fitting lid that prevents them from crawling out. They are safe to keep with aquarium plants but may accidentally uproot new plants in loose substrate when they crawl past them.
Snails and slugs come out when it rains because they need a high degree of humidity to carry out some important physiological activities, such as feeding and reproduction. They also make small holes in the ground to lay their eggs, a task that is made more difficult by hard, dry soils.
The animals lose memories when put under multiple pressures
Snails get stressed out, too—and it's not good for them either. Scientists have found that multiple sources of stress can impair the memories of the slimy gastropods.
As part of their mating ritual (yes, they have a mating ritual), some land snails shoot each other with “love darts”. Researchers previously thought these projectiles of passion might be “gifts” of calcium, but understandings have progressed.
They will always be hungry, but ideally they should never be so hungry they turn to digging through the substrate, eating your plants, climbing out of the tank (or at least attempting to) or becoming lethargic.
Killing them right away gets you through it quicker, while poison pellets and nematodes drag it out. How do you kill them? Real die-hards cut them in half with sharp scissors (🤢). If you can't bring yourself to do that, you can instead drown them in beer, sugar water, or boiling water.
But in general, aquarium snails can live for 2-5 years, and if they are taken good care of, they can live for up to 15 years.
A snail infestation can often be caused by excess food in your aquarium. The snails feast on the excess food and thrive. Stop them in their tracks with routine maintenance, removing excess food after feeding time and avoiding overstocking. Once the snails have taken over they can be tricky to remove.
Does a snail recognize its owners? It is unlikely that a snail will recognize its owners as some other pets would. This isn't to say it's impossible, but snails have bad eyesight.
Snails and slugs need to be wet, so you're most likely to see them when it's raining. They don't like it when it's too hot or too cold. If it gets too dry, snails can go into a dormancy called aestivation, or if it gets too cold, they might hibernate.