Bed Bugs, also known by their scientific name Cimex lectularius , are parastic insects that feed on blood. The most common ones prefer to feed on human blood. Bed Bugs are mainly nocturnal and can feed without being noticed. Some of the side health a effects include skin rashes, psychological effects and some people are even allergic symptoms. They were on the verge of extinction in the early 40s but they have recently made a comeback.