Sacred Haven of Debauchery

Rats are nasty pests that spread diseases and rummage through garbage, while hamsters are fluffy pets that run in a wheel.

In the city, rats rummage through garbage earlier than they used to, when they rummaged through barns like house mice, and hamsters used to rummage through fields like field mice. If you put a rat in a cage, feed it, and give it water, it will also happily run in a wheel and won't want to run to the garbage dump, and it won't catch any diseases there... and a hamster, if raised in nature, can also spread disease.