vermin

noun, plural ver·min.

1. noxious, objectionable, or disgusting animals collectively, especially those of small size that appear commonly and are difficult to control, as flies, lice, bedbugs, cockroaches, mice, and rats.
2. an objectionable or obnoxious person, or such persons collectively.
3. animals that prey upon game, as coyotes or weasels.

noun

1. (functioning as plural) small animals collectively, esp insects and rodents, that are troublesome to man, domestic animals, etc
2. plural -min an unpleasant, obnoxious, or dangerous person

n.

c.1300, “noxious animals,” from Anglo-French and Old French vermin, from Vulgar Latin *verminum “vermin,” possibly including bothersome insects, collective noun formed from Latin vermis “worm” (see worm). Extended to “low, obnoxious people” by 1560s.

n. pl. vermin

1. Any of various small animals or insects, such as rats or cockroaches, that are destructive, annoying, or injurious to health.