"Vermin hunting" refers to the act of intentionally seeking out and exterminating small pests or animals that are considered harmful or troublesome, such as rats, mice, or insects. Full definition
It is interesting that aggressive behavior is actually due to their being bred for vermin hunting. (animalbehaviorcollege.com)
Terriers and Dachshunds «go - to - ground» in simulated vermin hunts; retrievers, pointers, setters, spaniels, and Beagles, Bassets, and coonhounds prove their prowess in the field; sighthounds run lickety - split after a plastic bag in lure - coursing events; and herding dogs practice their skills on sheep and ducks. (canismajor.com)
Terriers are often categorized as being difficult to housetrain and these mostly include the smaller, working terriers bred as vermin hunting dog such as rat terriers and Jack Russells. (dailydogdiscoveries.com)