This is when the bearded dragon will stand high on three legs and will raise the remaining leg in the air and wave it in a circular motion. There are a couple of possible meanings when a bearded dragon waves it's arms. One meaning is species recognition. If a bearded dragon waves at another bearded dragon, it tells the other dragon that he/she is aware of their presence. Another meaning is submission. A bearded dragon may wave his or her arm whenever they are approached by a larger bearded dragon or whenever a larger animal approaches the dragon.
Head bobbing is more common in males and it when a bearded dragon will repeatedly raise and lower their head. Head bobbing is generally used as a sign of dominance between two dragons. Males will head bob at females to show their dominance during breeding. Other times two bearded dragons will head bob at each other as a sign of territorial aggression. Generally, the faster the head bob the more threatening. If a bearded dragon is head bobbing another dragon quickly, it's generally for territorial reasons. However, if a bearded dragon slowly head bobs another dragon, it can be a sign of submission.
Digging is when your bearded dragon will begin digging a hole in his or her tank. One reason bearded dragons can be digging is because they are trying to create a small basking area that is more comfortable. Bearded dragons can sometimes do strange things, but this can sometimes be the reason. If your bearded dragon is a female, she will begin digging and moving things around in her tank to create a place for her to lay her eggs.