We have a Double Nape Amazon. We have had him since he was 2. He is now 37. We originally lived in Hawaii, moved to Oregon and then Idaho. We never had a problem with feather plucking until the last two winters. We have been to the vet, changed foods, moved the cage, increased interaction, used aroma therapy to just name a few. The last two years he has started plucking about the middle to end of September. Last spring he let his feathers grow back out but started plucking again this September. It appears that he may let them grow back in this summer but it remains to be seen. A guest in our home who is the daughter of a bird breeder suggested that we may need to try a humidifier. We have purchased one but are wondering how much of the day it needs to be on. Are their any suggestions or "rules of thumb". I selected one that has both warm and cool mist. I didn't invest in an expensive one yet. We kind of wanted to see if this seems to work before we really invested big money. We have tried to many things already. Our vet said it is odd that they start plucking this late life and that something is definitely bothering him...the question is what but the humidity thing kind of made sense. Any suggestions?