The dog suddenly barks fiercely at the door because the dog saw or heard something. Dogs' hearing is very sensitive, and most dogs maintain a high degree of alertness at all times, so they will bark when they hear any abnormal movement. When the movement disappears, the dog will stop. If the dog has a bad habit of barking, the owner should stop and train the dog in time.

Tip:

Dogs are very loyal, so under normal circumstances they will not yell at their owners. When dogs bark at their owners, Most of the reasons are because the dog wants to attract the owner's attention and let the owner play with it, or when it is time to go out to play, the dog barks to remind the owner.