Border Terriers have earned more American Kennel Club (AKC) Earthdog titles than any other terrier. An AKC earthdog test is not true hunting, but an artificial, non-competitive, exercise in which terriers enter 9 in (23 cm) wide smooth wooden tunnels, buried under-ground, with one or more turns in order to bark or scratch at caged rats that are safely housed behind wooden bars. The tests are conducted to determine that instinctive traits are preserved and developed, as the breed originators intended for the dogs to their work. While earthdog tests are not a close approximation of hunting, they are popular in the U. S. and in some European countries because even over-large Kennel Club breeds can negotiate the tunnels with ease, dogs can come to no harm while working, and no digging is required. Since Border Terriers are "essentially working terriers", many Border Terrier owners consider it important to test and develop their dogs' instinct. These tests also provide great satisfaction for the dogs. The American Working Terrier Association (AWTA) does conduct "trials"; where the dogs instincts are tested, and then judged to determine a "Best of Breed" Earthdog.