do you switch the toys out daily? Giving him somethign new everyday in HIS HOUSE? Do you have foraging toys? Also what about his diet? Do you give him things to chew on and take apart?
Sound like to me that he is boared.
Rearrange his cage weekly also. Perches, dishes, everything put in a new spot.
It also just might be obssesive habits that can't be stopped. Try all the things I noted above before we jump to conclusions.
Parrots - Feather plucking in parrots - Learn causes and remedies for feather plucking and feather chewing.
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"Humans are the only animals that are mean on purpose"
Teal- Blue and Gold Macaw
Ellie - Mollucan/umbrella cockatoo hybrid