The common tern preferentially hunts fish long. The species caught depend on what is available, but if there is a choice, terns feeding several chicks will take larger prey than those with smaller broods. The proportion of fish fed to chicks may be as high as 95% in some areas, but invertebrate prey may form a significant part of the diet elsewhere. This may include worms, leeches, molluscs such as small squid, and crustaceans (prawns, shrimp and mole crabs). In freshwater areas, large insects may be caught, such as beetles, cockchafers and moths. Adult insects may be caught in the air, and larvae picked from the ground or from the water surface. Prey is caught in the bill and either swallowed head-first, or carried back to the chicks. Occasionally, two or more small fish may be carried simultaneously. When adults take food back to the nest, they recognise their young by call, rather than visual identification.