Sticklebacks have small spikes on their back and this makes them quite easy to find on a pond dip. They eat small fish and pond insects. Larger fish, such as the roach, eat them.
Sticklebacks can grow up to 4 centimetres long. The tiny ten-spined stickleback is the smallest of Britain's freshwater fish.
Go to the Pond Library to learn more about sticklebacks.