What changes the behavior answer
If the bird is calm, perched comfortably, and grinding softly before rest, that is usually normal contentment.
Read the body with the sound
Relaxed grinding usually comes with settled posture, soft eyes, and normal breathing. The bird should still eat and behave normally when awake.
Do not confuse warning sounds
Hard clicking, lunging, hissing, open-mouth breathing, repeated face rubbing, or beak injury are different issues.
Support normal beak use
Safe chewing, natural perches, good diet, and vet checks help keep beak wear and comfort on track.
When to worry
If the sound is new and paired with appetite change, swelling, injury, breathing trouble, or trouble cracking food, call an avian vet.