To avoid light, bedbugs hide in the seams of mattresses and crevices of bed frames, walls, and furniture during the day.5,7 They are attracted to human hosts by warmth and carbon dioxide; these hosts generally sleep within 3 to 7 feet (1 to 2 meters) of the bedbugs’ hiding places.8,9 Feeding usually takes place just before dawn.10 Bedbug saliva contains several anesthetic, vasodilatory, anticoagulant, and proteolytic compounds that allow the insects to feed undetected for five to 10 minutes. Three of these compounds have been identified as instigators of the subsequent hypersensitivity reactions that may be noticed when the host awakens.11–14
Unlike those of other insects, bed bug bites may sometimes appear in tight lines of multiple, small, red marks where multiple bed bugs have fed along an exposed area. Bed bug bites can cause itchiness. Initially, a victim may detect a slight burning sensation. The burning area then develops red bumps, known as papules or wheals (rash). In extreme cases, bites may swell dramatically or turn into blister-like skin inflammations.