Nigel Cattlin / Eggs of Golden apple snail / Channelled apple snail (Pomacea caniculata) in a Rice (Oryza sativa) paddy, Luzon, Philippines

Philippe Clement / Lined top shells (Phorcus lineatus) in a rock pool, Normandy, France, June

Philippe Clement / Lined top shells (Phorcus lineatus) and Common european limpets (Patella vulgata) in a rock pool, Normandy, France, June.

Steve Downer / Juvenile Common frog (Rana temporaria) on back of a Common snail (Cornu aspersum), UK, June.

Steve Downer / Juvenile Common frog (Rana temporaria) on back of a Common snail (Cornu aspersum), UK, June.

Brian Bevan / Two Giant african snails (Achatina fulica) emerging from their shells and looking around, UK. Captive.

Steve Downer / Grove snail / brown lipped snail (Cepaea nemoralis) with juvenile riding on its back, Birmingham UK June.

Steve Downer / Banded snail (Cepaea nemoralis) on rear of a backlit rose leaf, controlled conditions.

Konrad Wothe / Giant snail (Megalobulimus) in a lowland rainforest, Panguana Reserve, Huanuco Region, Peru.

Ammonite / Close up of a Common snail (Cornu aspersum) moving, with Woodlice (Oniscidea). Controlled conditions.

Ingo Arndt / Caddisfly (Limnephilus sp.) case built of sticks, wood fragments, seeds, snail shells and plant stems, Germany, November.

Ingo Arndt / Foot of Banded snail {Cepaea sp} viewed from below