The common name of the insect species Cimex lectularius is the bed bug, more precisely the common bed bug.
Cimex lectularius is a small, wingless, blood-feeding true bug in the family Cimicidae. It is especially adapted to living around people and usually hides in mattress seams, furniture cracks, wall gaps, and other sheltered places rather than remaining on the host’s body. It typically feeds at night and returns to cover afterward.
The species has five immature nymphal stages, and each stage requires a blood meal before the insect can molt to the next one. Females can lay hundreds of eggs under favorable conditions. Bed bugs spread mainly by crawling or hitchhiking in luggage, clothing, furniture, and other belongings.
A common mistake is to confuse the common bed bug with the tropical bed bug, Cimex hemipterus, a related species found mainly in tropical regions. Bed bugs are also not head lice or carpet beetles, and current evidence does not establish them as effective transmitters of human infectious disease.