VERMIN

[plural] [noun] - small animals and insects that can be harmful and which are difficult to control when they appear in large numbersFlies, lice, rats, foxes and cockroaches can all be described as vermin.Farmers are involved in a constant battle to control vermin which ruin their crops and damage their livestock.People who are unpleasant and harmful to society can also be described as vermin.He thought all terrorists were vermin and that prison was too good for them.