How Long Do Garden Snails Live? Lifespan in Gardens and Wild

How long do garden snails live in the wild?

The garden snail (Cornu aspersum) starts life as a pearly-white egg, one of a clutch of roughly 50–100 laid in a hole in damp soil. The young hatch after about two to four weeks with a thin, fragile shell, and this is the most dangerous stage of their lives. Tiny snails dry out quickly, are easily crushed and are eaten by beetles, birds and many other animals.

Survivors grow through spring, summer and autumn and rest during winter and dry spells. They become adults at about 10 months old in warm places such as South Africa and at about two years in cooler or drier places such as southern California. Once adult, they can mate and lay eggs over one or more seasons. The typical lifespan in the wild is about two to three years, and some individuals live longer.

How long do snails live in captivity?

In captivity, garden snails are protected from predators, frost and drought, the main causes of death in the wild, so they often live longer than wild snails. Snail farms and laboratories also show how fast the species can grow: well-fed garden snails can become sexually mature within about three and a half months of hatching. Records of exact ages for individual captive garden snails are scarce, so figures quoted online should be treated with caution.

How can you tell if a snail is an adult?

The shell gives the best clue. A young garden snail has a thin, sharp edge around the shell opening, where the mantle is still adding new material as it grows. When the snail reaches full size, it builds a thick, white rim, called the lip, which curls slightly outward. After that, the shell stops growing.

This means a snail with a lip is an adult, but the shell cannot reveal whether it is two or four years old. In some species, such as the Roman snail, scientists estimate the age of young snails from the marks left by winter pauses in growth. How the shell is built in the first place is covered in how do snails grow their shells?

What kills garden snails?

Most garden snails die from predators, water loss, cold or parasites.

• Predators. Song thrushes famously smash snail shells on a favorite stone, called an anvil, and blackbirds, other birds, shrews, rats, frogs, toads, slow worms, ground beetles and glowworm larvae also eat snails. The European hedgehog is another snail eater.
• Drought. Snails lose water through their skin and mucus. Hot, dry weather can kill those that cannot find shelter.
• Cold. Garden snails can survive temperatures down to about -5 °C (23 °F) by changing the chemistry of their body fluids, but long, hard frosts kill many, especially young snails.
• Parasites and disease. Nematode worms and other parasites infect garden snails and can shorten their lives.

People are a further danger: snails are crushed on paths and roads, collected for food in some countries and removed from gardens.

How hibernation and estivation help snails survive

Garden snails survive bad weather by switching off. In dry summers they estivate: they pull into their shells, often stuck to a wall or plant stem, and seal the opening with a thin, papery film of dried mucus called an epiphragm. In winter they hibernate in the same way, usually in sheltered crevices, compost heaps or leaf litter. Their heart rate and breathing slow down, and they use very little energy. They are one of many animals that hibernate.

These resting periods can last weeks or months, and they let snails live through seasons when they could not otherwise survive. The most famous example involves a desert snail from Egypt. In March 1846, a specimen thought to be dead was glued to a card at the British Museum in London. In March 1850, staff discovered it was still alive; after a soak in water, it came out of its shell and began to crawl. That is the likely origin of the popular claim that snails can sleep for three years. Garden snails do not normally rest that long.

Which snails live the longest?

Snail lifespans vary widely between species. Larger snails that grow slowly tend to live longer.

Some rare snails are long-lived too. The Hawaiian tree snails of the genus Achatinella grow slowly and live for many years. The last known individual of Achatinella apexfulva, a snail named George, died on January 1, 2019, at about 14 years old, and its species is now believed to be extinct. Longer lifespans still are found among other mollusks, as shown in our list of the longest-living animals.