Small to medium-sized birds of prey which resemble the Accipltridae in having hooked bills, sharp curved talons, and remarkable powers of sight and flight. Like other raptors they are mainly diurnal, although a few are crepuscular. Some falcons kill flying birds in a surprise attack, often by stooping at great speed (e.g. Peregrine); others hover and then swoop on prey on the ground (e.g. Common Kestrel) and several species hawk insects in flight (e.g. Eurasian Hobby)