Eggs to adults
Snails hatch with their shells already on and grow them bigger as they go. Here’s the year of a garden snail, and what snails and slugs do when it’s too cold or too dry.
Both at once
All slugs and most snails are hermaphrodites: each one is both male and female. Royal Horticultural Society: 10 fun facts about slugs (7 March 2024) Even so, brown-lipped snails need to pair up before they can lay eggs, which they then bury in soil. The Wildlife Trusts: Brown-lipped snail
Most slugs can fertilise their own eggs if they have to, though mating is the usual way. Royal Horticultural Society: 10 fun facts about slugs (7 March 2024)
Nests and eggs
A garden snail digs a nest about 2.5 to 4 cm deep with its foot and lays its eggs inside. Dekle & Fasulo, Brown garden snail, University of Florida IFAS Featured Creatures (EENY240) A garden snail lays 30 to 120 round white eggs at a time, each about 3 mm across. Dekle & Fasulo, Brown garden snail, University of Florida IFAS Featured Creatures (EENY240)
Hatchlings
In summer, garden snail eggs hatch in about two weeks. The babies already have shells, but they are thin and see-through. Dekle & Fasulo, Brown garden snail, University of Florida IFAS Featured Creatures (EENY240) Garden snails grow to 16 to 20 mm across in their first year and 26 to 33 mm by their second. Dekle & Fasulo, Brown garden snail, University of Florida IFAS Featured Creatures (EENY240)
How long they live
Most snail species only live for one to two years, but in a long wet season they can lay eggs almost all the time. Natural History Museum, London: For the love of snails and slugs
Winter sleep
In winter, snails hibernate in a sheltered spot. Many seal their shell with a plug of mucus first, and they are often found clumped together. Natural History Museum, London: For the love of snails and slugs
Summer rest
When it is too dry, snails can go into a sleep-like rest called aestivation. Natural History Museum, London: For the love of snails and slugs In dry weather a garden snail can stick itself to a surface or close its shell with a papery seal called an epiphragm. Dekle & Fasulo, Brown garden snail, University of Florida IFAS Featured Creatures (EENY240)
Some land snails live above the snow line, and some desert snails stay inactive for years between rains. Britannica: Gastropod
Next: what they eat →