Vermin

Webster's Dictionary of the English Language

·noun ·sg & ·pl An animal, in general.

II. Vermin ·noun ·sg & ·pl Hence, in contempt, noxious human beings.

III. Vermin ·noun ·sg & ·pl A noxious or mischievous animal; especially, noxious little animals or insects, collectively, as squirrels, rats, mice, flies, lice, bugs, ·etc.