Treeing is a critical skill for many hunting dogs. In a successfully executed tree move, the hunting dog will force small game animals up a tree where they are easier for the hunter to pick off. But sometimes, a fleeing animal may escape into a burrow or den at the base of a tree. It is dangerous for a hunting dog to enter a hole with prey. You'll want to correct this behavior to prevent potential injury.
Keep your dog on a long training leash during training sessions. Competent hunting dogs do not always need one, but puppies and hunters in training do. You can conduct initial training by hiding dummies and executing practice hunts, but only live game will burrow.
Reward the dog for every successful tree with a treat or the quarry. A successful tree only occurs if the dog is barking at the base of the correct tree. If there is no barking, if your dog is at the wrong tree or if he tries to dig into a den, he gets no reward.
Use the leash to prevent the dog from treeing in a hole. Do not use the leash to administer corrections or hurt the dog; use it as a preventative tool. If the dog tries chasing prey into a den or hole, pull him out, skip the reward and move on to the next animal.
Continue to reward the dog only for perfect treeing execution. As the dog learns which behaviors are desired on the hunt, he will naturally adopt them over others.