Hosts
The bedbug is a parasitic insect that lives on the blood of humans and animals. For many years, scientists believed that bats were the insect's first host. However, they recently discovered that bedbugs have been on the planet much longer than bats, namely since the time of the dinosaurs. The actual first host of the bedbug has yet to be determined. Chances are slim that it was a dinosaur, given that dinosaurs did not build nests out of twigs and leaves. The insects feel most at home in warm nesting places, such as a bird's nest or a human bed.
Other bed dwellers
Fortunately, the chance that there is a bedbug in your bed is very small. The majority of bed dwellers, mostly bacteria and mites, are considerably less bothersome. Many bacteria in your bed come from your own body and therefore are not harmful. In addition, there are harmless mites who live off the tiny flakes of skin that end up in the bed. They are invisible to the naked eye.