How big are bed bugs?

Bedbug adults are about 1/4 inch long and equally wide; they become plump after feeding. The first-stage nymphs are about 1/16 inch long and go through five stages to reach adulthood.

Bedbugs are small enough to hide in just about any crack or crevice. They usually come out at night, and adult bedbugs are visible to the naked eye. A flashlight and magnifying glass are often required to spot these insects. They like to hide in mattresses, box springs and bed frames close to their source of blood, which gives them their name. Bedbugs crawl as quickly as ants, but do not fly or jump. They only feed on blood; they prefer human blood but settle for animal blood.