Cimex lectularius, commonly known as the bed bug, is a flea-like true bug that dines on the blood of its hosts (that would be you and me). In prehistoric times, bed bugs absolutely loved our warm caves, and now they love our warm houses and especially our beds and bedding.
As a logophiliac, I find the etymology of the bed bug fascinating. In Medieval Europe, the word bug or bugge originally referred exclusively to bed bug. (In present day, we call many things bugs: it’s the informal moniker not just for other insects, but for microscopic germs, or diseases caused by the germs.) Depending on where you come from, a bed bug could have other names: wall louse, mahogany flat, crimson rambler, chilly billies, heavy dragoon, chinche bug, or redcoat.
No matter what it’s called, this true bug is also a true parasite. That means they are pretty much good for nothing.
Some entomologists say that if an insect is a parasite found exclusively in human dwellings (and not in nature), killing it off will not upset the balance of the ecosystem.