Paul Hobson / Grass snake (Natrix natrix) swimming amongst duck weed, Oxfordshire, UK

John Cancalosi / Green Frog (Rana clamitans) among duck weed on water surface. New York state, USA, September.

Loic Poidevin / Female Mallard Duck (Anas platyrhynchos) on water among flowering pond weed. The Vendeen Marsh, French Atlantic Coast, April.

Fabio Liverani / Wolf spider (Pardosa wagleri) carrying young on its back over water on duck weed, Lake Cernika, Slovenia

Fabio Liverani / Wolf spider (Pardosa wagleri) carrying young on its back over water on duck weed, Lake Cernika, Slovenia

Tom Vezo / American alligator in duck weed {Alligator mississippiensis} Texas, USA