Garden pest control - Snails (Description and control instructions)

Snails are similar in most ways to Slugs apart from their shell. This is their most striking feature and close study reveals wonderful geometric patterns. Unless you find them a gastronomic delight and comsume the palatible species, the fascination ends there, since they can be just as pestilent as their slimy cousins.

The Garden Snail Helix aspersa (above left) can grow to 38 mm wide with five dark bands on a fawn background. They are usually found during the day behind stones and clinging to walls where they are sheltered by a climbing plant. They become active at night or occasionally during dull moist days, when they can avoid predators and drying sunshine. They can live for about three years.

The White-lipped Banded Snail is about 16 mm wide and can be all yellow, but usually there are a number of darker bands in variable colours and numbers.

As with slugs each snail has male and female reproductive organs, but they do mate to exchange sperm. This occurs on a warm, wet night and afterwards they part to go and lay up to 40 spherical, fertilised eggs in a shallow depression. After a month small replica snails hatch out and the shell enlarges as they grow.

Major predators are the Song Thrush and Blackbirds which break the shell on a stone.

Snails are a bit easier to find and easier to pick up, due to their shells, so inspect the undersides of objects and pick them off. Ground-feeding birds such as Thrushes and Blackbirds love them and like a boulder to smash them against. See the monograph on Slugs for more methods to defeat them.