The embryos of Helix pomatia undergo development that is typical of veliger larvae. In the case that an embryo becomes dehydrated, it is usually able to survive. The snails emerge from their shells three to four weeks after they are deposited in a hole dug by their parent, depending on both the temperature and humidity. Each newly-hatched snail typically weighs twenty-seven milligrams and has both male and female reproductive organs. The snails live in the hole dug by the parent for a little over a week, feeding on the empty eggshells.
Shells grow incrementally until they reach maturity. Growth of the shell is inhibited by adverse weather conditions such as extreme heat or dryness, but eight hours of sunlight is optimal. Shells cannot reach full development unless they are able to access a rich calcium carbonate food-source
Development - Life Cycle: metamorphosis