Bed bugs are small, brownish, flattened insects that feed solely on the blood of animals. Although the common bed bug (Cimex lectularius) prefers feeding on humans, it will also bite other warm-blooded animals, including dogs, cats, birds and rodents. It has done so since ancient times; bed bugs are mentioned in medieval European texts and classical Greek writings back to the time of Aristotle.
Bedbugs lurk in cracks and crevices and they've been living on human blood for centuries. Though they aren't known to transmit disease or pose any serious medical risk, the stubborn parasites can leave itchy and unsightly bites. However, bedbugs don't always leave marks. The best way to tell if you have a bedbug infestation is to see the live, apple-seed-size critters for yourself. Unfortunately, once bedbugs take up residence in homes and businesses, they can be difficult to exterminate without professional help.
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.