Much like dogs, though not as beloved, rats are our constant companions. Of the dozens of species in the genus Rattus, the most familiar are those which commonly live among us: the brown rat (also known as the Norway rat or sewer rat) and the black rat (also called a house rat, roof rat, or ship rat).

Some rodents that we call “rats” are not true members of Rattus, including the pack rat, naked mole rat, and giant pouched rat.

Rats are notorious stowaways that migrated around the world along with humans; today they live wherever Homo sapiens are found, on every continent except Antarctica. Rats are not just an inescapable feature of city living: In some ecosystems, particularly on islands,