Beak grinding is a frequent bird behavior that most parrot owners experience at one time or another. This is a side-to-side movement of the top and bottom beak mandibles against each other. Most people hear this sound as they are putting their parrots to sleep for the night, or while the birds are quietly napping. If you haven’t heard it, parrots may be beak grinding once they are covered and the lights are off, after you have left the room. The purpose of beak grinding is debatable- whether it is to keep the beak in shape, or a subtle signal to other flock members. General consensus is that it is a relaxed and content behavior!