Earthdog trial

An earthdog test tests the working ability and instinct of the small, often short-legged terriers or Dachshunds. These dogs were bred to hunt vermin and other quarry which lived in underground dens. Earthdog den tests involve man-made tunnels that the dogs must navigate, while scenting a rat, "the quarry." The dog must follow the scent to the quarry and then "work" the quarry. Depending on the sanctioning organization, “working” means barking, scratching, staring, pawing, digging; any active behavior. The quarry is protected at all times by wooden bars across the end of the tunnel. The hunting encounter is controlled, and neither the dog nor the quarry (usually two rats) are endangered by the activity.
In Canada, earthdog tests are sanctioned by the Canadian Kennel Club (CKC). In the United States, two major organizations sanction earthdog tests: the American Kennel Club (AKC) and the American Working Terrier Association (AWTA).
AKC earthdog tests.
AKC earthdog tests are intended as noncompetitive venues in which the handlers may gauge their dog’s natural hunting aptitude when presented with an underground hunting situation. According to the AKC General Regulations for Earthdog Tests, the noncompetitive program begins with a basic introduction to den work and quarry, progressing through gradual steps to the point where the dog can demonstrate that it is willing to perform the required tasks, including seeking its quarry and working it underground.
Eligibility.
Dogs that are registered with the AKC and are six months of age or older may participate in AKC Earthdog tests. They do not need to be intact, and purebred dogs that have been assigned “Indefinite Listing Privilege” (ILP) numbers, may also participate. In comparison to the American Working Terrier Association (AWTA) tests, fewer breeds are permitted in AKC tests, with mixed breeds being excluded altogether. The following breeds are classified as eligible to participate in AKC Earthdog tests:
Program.
AKC earthdog tests differ from AWTA trials in that the AKC program is broken down into several more levels of increasing difficulty: 
AWTA earthdog den trials.
The AWTA predates the AKC earthdog program and was founded to promote and test the working abilities of terriers and dachshunds.
The AWTA awards Certificates of Gameness to terriers and Dachshunds who achieve a score of 100% in the AWTA open class. To qualify in the open class, a dog must be released near the trial's earth tunnel opening, find its way into the tunnel and reach the quarry, all within 30 seconds (50% of score) and then “work” the rat continuously for a full 60 seconds (remaining 50% of score). Timing starts from the moment the dog is released by the handler. The dog may enter the tunnel and come out or walk around the tunnel, but it must get to the rat within the time allotted. However, once it reaches the rat, it must remain with it for the aforementioned 60 seconds.
The following breeds are recognized (and therefore able to compete) in AWTA den trials:
Other small terrier breeds may compete in the miscellaneous class.