The name "bedbug" is derived from the insect's preferred habitat of houses and especially beds or other areas where people sleep or spend time. Bedbugs, though not strictly nocturnal, are mainly active at night and are capable of feeding unnoticed on their hosts. Adult bedbugs are reddish-brown, flattened, oval, and wingless. Bedbugs have microscopic hairs that give them a banded appearance. Adults grow to 4-5 mm in length and 1.5-3 mm wide. Once hatched, bed bug nymphs are no larger than a pinhead, closely resembling the adults, but smaller and lighter in color until they reach maturity. The nymphs mature rapidly, shedding their exoskeleton as they grow larger after each feeding. Bed bugs feed exclusively on blood, preferring human blood.