My Uncle Abe was a surgeon, but, in his spare time, also a "gentleman farmer". That is, he owned a farm, but the work was done by two hired families, which lived in two houses at opposite ends of the farm. Farms are usually attacked by pests, among them small mammals such as groundhogs, foxes, etc. My uncle used standard DDT for the insects, but refused to put out poisoned bait for the small mammals.

Instead, he had a pack of a dozen large dogs, Dobermans, Weimaraners, German Sheppards, etc. Dogs were fed twice a day. They were kept at night at East end of the long, narrow farm. In the morning, they were fed their morning meal at the opposite (West) end of the farm, so they had to walk a mile for breakfast, patrolling the entire farm the first time. At evening, they were fed back where they slept, the East end, so they had to patrol the entire farm twice each day. My uncle's farm was never bothered by groundhogs, foxes, etc because there are no such animals stupid enough to tangle with a pack of a dozen large dogs.