What domestic animals are free to roam at night in Disney parks?

The Disneyland Cats have been around for as long as any of us can remember. The cats were able to emerge at night to a relatively empty park, and they could hunt in peace. Someone in the Disney company must have had a pretty brilliant idea. The cats weren’t bothering anyone—feral cats, by nature, are scared of humans—and they were doing a much better job with pest control than any human exterminators were likely to do. So the cats were put to work. More accurately, they were allowed to continue doing the work they were already doing, but now it was with Disney’s blessing and some payment.

Source: The Cats of Disneyland