Bedbugs are blood-feeding insects. They bite people at night while they are sleeping. Scientists think that the bedbugs find the host by sensing the body temperature and the carbon dioxide that the person exhales.
The bedbug's mouth acts like a tiny saw to cut through the host's skin. Even so, for most people, bedbug bites are not painful. In fact, most people do not wake up during the bite or the feeding process.
The size of the bedbug determines how long it feeds. Immature nymphs only feed for three or four minutes. Adult bedbugs may feed for 10-15 minutes. Bedbugs sometimes make more than one bite during one feeding.
During the feeding, the bedbug inserts two tiny tubes into the host/victim's skin. The bedbug uses one tube to inject saliva into the host's skin. The saliva prevents the blood from clotting while the bedbug feeds. The bedbug uses the other tube to draw blood into its mouth.
Some people are allergic to the bedbug's saliva. These people usually develop skin irritation and itching at the site of the bite. A few people who are allergic to the saliva develop a welt at the bite site. A small number of sensitive people develop swelling beyond the area of the bite.
People who develop itching or welts may blame mosquitoes, fleas, or spiders for the bites. Since bedbugs stay hidden, people seldom see them. To identify the cause of the bite, it is usually necessary to use the clues that the bedbugs leave behind.
Bedbugs often leave small blood spots on sheets and bedding. This happens when the victim rolls over and crushes a bedbug after it has eaten. The spots also happen if the bedbug “overeats” and blood spills on the bed.
Bedbugs also leave dark fecal stains near their hiding places. People will usually find these stains on the bed frame, the mattress, the box spring, and even on the baseboard behind the bed.
Since the bedbug bites are not painful, a thorough inspection is the best way to confirm whether bedbugs have been active. Many people prefer to call a pest control professional to do this inspection.