Colonial bats can harbor ectoparasites, from bat flies to mites, fleas, and even bed bugs. The good news is that most bat parasites are highly host-specific. Unless they’re starving, they much prefer to remain with their bat hosts. It may also be reassuring to know that disease transmission from bat parasites to humans is exceedingly rare, if it occurs at all. In fact, in a lifetime of studying bats, I’ve never heard of it.