Wyoming’s Norway rat record is a one-county affair: every mapped report comes from Albany County, home of Laramie. That’s fitting for a rat that has never lived wild in the West. Norway rats arrived with people and stay close to them, in towns, farmyards, and feedlots, and a university town full of active observers is exactly where reports would pile up. The empty counties on the map say more about reporting than about rats.
The dates scatter across the calendar, with small bumps in September, December, and February. This is an animal that forages and breeds in every season, and it becomes most visible when it moves into buildings ahead of winter or when someone finally sets a trap.
Wyoming’s files treat the rat as what it is, an introduced species with no conservation listing, and NatureServe marks its state rank as not applicable. It isn’t native to Wyoming or to anywhere in the Americas. The interest in its record isn’t rarity but footprint, tracking where a species that lives off human habitation has taken hold in a mostly rural state.
Full species profile
