Housing for domestic pigeons are often called pigeon lofts. Columbidae is a bird family consisting of pigeons and doves. Pigeons and doves may be sexually monochromatic or dichromatic. By Roman times pigeons and chickens were the principal poultry. Seeds and fruit form the major component of the diets of pigeons and doves. A Pigeon Policy Committee made decisions about the uses of pigeons in military contexts. Domesticated pigeons are used as homing pigeons as well as food and pets. Eventually researchers plan to develop HI-MEMS for dragonflies, bees, rats and pigeons. Early attempts along these lines focus on the behavior of rats and pigeons. A more effective tactic to reduce the number of feral pigeons is deprivation. Two parasites have been recorded on passenger pigeons. Taken together the receptor responsible for magnetosensitivity in homing pigeons remains uncertain. In Northern California, elderberries are a food for migrating band-tailed pigeons. They repeated this performance in the trap and team clay pigeons events. Cave 15 door frame has carvings of pigeons eating corn.