Wild Wonders of Europe / Smit / Great pond snail (Lymnaea stagnalis) trying to survive in ponds in broadleaf forest during dry season, Gornje Podunavlje Special Nature Reserve, Serbia, June 2009

Jan Hamrsky / Freshwater snail (Radix auricularia), Europe, April, controlled conditions

Jan Hamrsky / Freshwater snail (Radix auricularia), Europe, April, controlled conditions

Jan Hamrsky / Freshwater snail (Radix auricularia), Europe, April, controlled conditions

Nick Upton / Two Great pond snails (Lymnaea stagnalis) grazing algae from submerged rocks in a garden pond, Wiltshire, UK, July.

Nick Upton / Great pond snail (Lymnaea stagnalis) grazing algae from a rock in a garden pond, Wiltshire, UK, July.

Jan Hamrsky / Freshwater snail (Stagnicola sp.), on stone underwater, Europe, July, controlled conditions

Jan Hamrsky / Freshwater snail (Stagnicola sp.), by the water surface, Europe, July, controlled conditions

Ashley Cooper / Snails aestivating on a fence post in the Coto Donana, Andalucia, Spain, June 2011

Laurie Campbell / Garden Snail (Helix aspersa) on rotten log in garden pond, Berwickshire, Scotland, June.

Remi Masson / Great pond snail (Lymnaea stagnalis) eating aquatic plant in a river. Alps, River Rhone, France

Klein & Hubert / European hedgehog (Erinaceus europaeus) and snail (Cepaea nemoralis) reflected in water, France. Controlled conditions.

Klein & Hubert / European hedgehog (Erinaceus europaeus) and snail (Cepaea nemoralis) reflected in water, France. Controlled conditions.

Nick Upton / Young boy reaching into plastic tank held by his mother for Pond snails he has caught whilst fishing in stream, Bristol, UK, October 2014. Model released.

Willem Kolvoort / Common water crowfoot (Ranunculus aquatilis) with Great Pond Snail (Lymnaea stagnalis) in garden pond, Holland. May.

Jan Hamrsky / Great pond snail egg mass (Lymnaea stagnalis) Europe, July, controlled conditions

Jan Hamrsky / Great pond snail (Lymnaea stagnalis) Europe, July, controlled conditions

Jan Hamrsky / Great pond snail (Lymnaea stagnalis) Europe, July, controlled conditions

Jan Hamrsky / Freshwater snail (Galba truncatula) Europe, May, controlled conditions

Wild Wonders of Europe / Lundgren / Great pond snail (Lymnaea stagnalis) Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Water boatman (Corixidae) on a Great pond snail (Lymnaea stagnalis), Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Great pond snail (Lymnaea stagnalis) Danube Delta, Romania, June.

Simon Colmer / Great Pond Snail (Lymnaea stagnalis) on white background, UK

Wild Wonders of Europe / Smit / Dried out pond with snails, algea, Gornje Podunavlje Special Nature Reserve, Serbia, June 2009

Nature Production / Big-ear Radix snail {Lymnaea auricularia} Wakayama, Japan

Simon Colmer / Close-up of eggs in egg case of Great Pond Snail (Lymnaea stagnalis), captive UK

Simon Colmer / Great Pond Snail (Lymnaea stagnalis) egg case, captive UK

Simon Colmer / Great Pond Snail (Lymnaea stagnalis) on pond plant, captive UK

Willem Kolvoort / Stone loach (Nemacheiulus barbatula) and Great pond snail (Lymnaea stagnalis) in brook in Holland

Willem Kolvoort / Ramshorn snail (Planorbis planorbis) and Chinamark moth larva (Nymphula nympheata) underwater on the leaf of the White water lily (Nymphaea alba) in garden pond, Holland

Willem Kolvoort / Great pond snail (Lymnaea stagnalis) and two Great ramshorn snails (Planorbis corneus) under leaf of White water lily (Nymphaea alba) garden pond, Holland

Willem Kolvoort / Great pond snail (Lymnaea stagnalis) at water surface to breathe, garden pond, Holland

Willem Kolvoort / Great ramshorn snail (Planorbis corneus) sand winning pit, Holland. This snail does not have enough pigment in its skin, the red colour is caused by haemaglobin.

Willem Kolvoort / Great ramshorn snail (Planorbis corneus) sand winning pit, Holland

Willem Kolvoort / Oval pond snail (Radix ovata) feeding on algae, sand winning pit, Holland

Willem Kolvoort / Great pond snail (Lymnaea stagnalis) at surface to breathe, sand winning pit, Holland.

Willem Kolvoort / Great pond snails (Lymnaea stagnalis) with European edible frog spawn (Rana esculenta) Holland

Willem Kolvoort / Ramshorn snail (Planorbis planorbis) in garden pond, Holland

Willem Kolvoort / Underwater view of White water lilies (Nymphaea alba) with Ramshorn snails (Planorbidae) in garden pond, Holland

Willem Kolvoort / Marsh snail (Lymnaea palustris) on Perfoliate pondweed (Potamogeton perfoliatus), sand winning pit, Holland

Willem Kolvoort / Marsh snail (Lymnaea palustris) on Perfoliate pondweed (Potamogeton perfoliatus), sand winning pit, Holland

Willem Kolvoort / Marsh snail (Lymnaea palustris) on Perfoliate pondweed (Potamogeton perfoliatus), sand winning pit, Holland

Willem Kolvoort / Ramshorn snail (Planorbis planorbis) feeding on algae on reed stem, Holland

Willem Kolvoort / Ramshorn Snail (Planorbis planorbis) juvenile, Holland

Willem Kolvoort / Mass of tiny Pond snails feeding on algae in lake, Holland

Willem Kolvoort / Eggs of Common bithynia {Bithynia tentaculata} Peat-bog lake, Holland

Willem Kolvoort / Common bithynia {Bithynia tentaculata} Peat-bog lake, Holland

Willem Kolvoort / Ear snail (Lymnaea auricularia) Holland