Bed bug

Mattresses, bed frames, upholstered furniture, cracks, and other indoor crevices near sleeping hosts.

Feeds primarily on blood, usually human blood, using piercing-sucking mouthparts. It typically feeds at night and hides afterward.

Flattened, wingless, reddish-brown adults hide during daylight and emerge in darkness. Females lay eggs in protected cracks; infestations spread mainly through luggage, clothing, furniture, and adjoining rooms.

Bites can cause itchy welts, allergic reactions, and sleep disruption, but bed bugs are not established vectors of human disease. They provide negligible ecological benefit indoors.