As urbanization took place, underground tunnels constructed by badgers became an increasing problem. Additionally, their homes, or badger setts were also cohabited by foxes, rabbits, rats, weasels and other vermin. So badgers were the elusive prey several breeds of terriers were bred to hunt.
The Badger Sett
Setts that had existed for generations of badgers grew to cover huge areas in both in width and depth. Every four feet or so there was junction where the sett branched in two or more directions. These lead to chambers in which the badger slept on a bed of moss or, grass or leaves. Often there were several beds in the same sett. The setts could also be in layers, where foxes, rabbits and other underground creatures lived. These might be on different levels, for example rabbits as well as badgers on the top layer, and badgers and foxes below in a second or even third layers below.
Digging out the Badger
"I know of one locality on the Quantocks where the holes occupy an area of woodland approximately one acre in extent...more than 50 holes were counted... the breeding chambers are often situated under roots of a tree or some large stone or boulder. The badgers would remove some of the earth from above the roots or stone, and on this platform one of the adults would lie with its face towards the entrance. It is this impregnable position it could can drop on any intruder".
The Badger Dig
As badgers are nocturnal, they are difficult to spot and even more difficult to catch. With an adult weighing up to 40 pounds, and possessing very large claws and teeth, not only did it require an extremely plucky terrier to face them, the terrier had to have the correct short legged construction to enable it to dig. He must also possess a rare blend of courage and intelligence to weave his way through dark, cold and damp passages relying almost entirely on his sense of smell and sound.
Bagging the Badger
The normal procedure was to find the sett occupied by a badger and send in a terrier. The dog was trained to find the badger but keep its distance. If it approached too near it could get badly mauled or killed. Its job was to prevent the badger from digging away. So if the badger turned to dig, the terrier would leap on it and give it a nip. This would make the badger turn again so the terrier would retreat. This often continued for some hours, while the diggers excavated the tunnels in the direction of the yelps of the terrier. When close enough, badger tongs would be used to drag the badger out. It would then be dispatched by putting it in a sack so it could be transferred to another district and released.
References and Further Reading
 Captain Jocelyn Lucas, 'The Sealyham Terrier' Pub. M.C. T.H.Crumbie Ltd, Halford Street, Leister UK 1922 'Badger Digging' Page 69
 Ernest Leal 'The Badger' Pub Penguin Books Ltd New Naturalist Monograph series 1948 Page Chapter 12 'Badger Sets and Life Underground' Pages 146 - 148