Vermin

An animal, in general.

A noxious or mischievous animal; especially, noxious little animals or insects, collectively, as squirrels, rats, mice, flies, lice, bugs, etc.

Hence, in contempt, noxious human beings.

any of various small animals or insects that are pests; e.g. cockroaches or rats; "cereals must be protected from mice and other vermin"; "he examined the child's head for vermin"; "boys in the village have probably been shooting vermin"