vermin

nouns

an irritating or obnoxious person
varmint, vermin
is derived from
verminous
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"
vermin
is derived from
verminous
is a type of (narrower)
any unwanted and destructive insect or other animal that attacks food or crops or livestock etc.
"he sprayed the garden to get rid of pests"; "many pests have developed resistance to the common pesticides"
pest