Bed bugs are small, brownish, flattened insects that feed on the blood of human beings but can suck blood from other animals as well. The common bed bug, Cimex lectularius, is the species most adapted to living with humans. It has done so since ancient times.
When not feeding, bed bugs hide in a variety of places: around the bed, near piping, seams and tags of the mattress and box spring, along with the cracks on the bed frame and head board. Unlike most public health pests, bed bugs are not known vectors for the transmission and spread of diseases. If a crack will hold a credit card, it could hide a bed bug.