Nymphs and adults feeding on Connecticut large brown bat
The batbug (Cimex adjuntus) is a close relative of the bedbug and may have evolved by
shifting to humans living in caves.
Most of the 90 or so species of bedbug feed on birds or bats. Only two are pests on humans: Cimex lectularius, and C. hemipterous. Although archaeological records show these parasites have been living with humans for thousands of years, their bites do not pass on any known diseases. A bedbug’s saliva contains anti- clotting proteins along with other glycoproteins and lipoproteins. A bite can cause immune responses to these proteins ranging from small red swellings to large blisters. Intense multiple feedings can result in bruising and even anemia in small children.
Bedbugs are wingless and so must stay within range of their hosts. An unfed bedbug’s flattened body lets it hide in narrow cracks, behind baseboards or in the crannies and seams of bed frames and mattresses. Generally nocturnal feeders, bedbugs are sensitive to low humidity, cold and high heat. Like most other blood feeders, bedbugs are usually first attracted to carbon dioxide in the host’s breath and then by body heat. Nymphs and adults can survive for a long time—up to six months—without feeding.