Garden Snail (Helix aspersa)
Although not the most popular if creatures we all learn about them at junior school, how they carry their homes on their back and in winter how they seal over the entrance whilst they sleep soundly inside.
The frequency of snails is not down to the abundance of food. They need calcium to form their shells and so are more common in chalk and limestone soil areas. They also have problems crossing sandy soil so are rarely found in such environments.
The Garden Snail is unpopular with gardeners for good reason, being very fond low growing fruit and vegetables.
They tend to be most active at night and spend the day behind flower pots and other sheltered places. It is apparently true that if you mark them and follow their movements that they will return to the same sheltered spot every morning after a night on the rampage amongst your plants.