Bed bugs mating. Coloured scanning electron micrograph (SEM) of a pair of bed bugs mating. Bed bugs (Cimex lectularius) are blood sucking insects, so called because they live in the beds of humans. Mating in bed bugs (and related families) is unique amongst the insects. The male (above) does not introduce his sperm into the female's vaginal opening. Instead he punctures the body wall of one of the female's abdominal segments and deposits his sperm in a sac. This is called traumatic insemination. Two to four gener- ations can be bred yearly, so that under suitable conditions infestation of a house can occur rapidly. Magnification x10 at 5x7cm size. Magnification: x22 at 6x4.5 inch size.