A pitiful image: a dog tucks its tail, lowers its gaze, whines and even hides behind its master. What exactly is behind this behaviour?

 

When dogs are frightened, they pinch their tail between their hind legs to hide the scent glands in the anal region. The scent glands at the anus have an individual scent that identifies the dog. Tucking the tail prevents the scent from being emitted and has the same effect among dogs as covering the face in humans.
The dog also sends a clear message by tucking its tail that it wants to be ignored. He is literally trying to make himself smaller. The tucked tail together with ears laid flat and lowered gaze signals to other dogs that he is not a threat.

Dogs are pack animals that clearly form their hierarchy within the pack. Each dog holds a certain rank, which determines the status of the individual dog. This rank determines the order in which the dogs eat. Through unmistakable signs such as tucking its tail, the dog expresses its low position.