Dogs are descended from wolves, and wolves are known to bury food for later consumption. This behavior is passed down to dogs, and it is one of the reasons why dogs bury bones.
If a dog is bored, they may start to bury bones as a way to entertain themselves. This is especially common if a dog is left alone for long periods of time.
Some dogs may bury bones as a way to cope with anxiety. This is especially common in dogs that have been abused or neglected.
Some dogs may bury bones as a way to hide food from other animals. This is especially common if a dog lives in an area with a lot of wildlife.
Some dogs may bury bones as a way to mark their territory. This is especially common in male dogs.
Some dogs may bury bones as a way to play. This is especially common in puppies.
There are many reasons why dogs bury bones. If you are concerned about your dog's bone-burying behavior, it is important to talk to your veterinarian.