Feather-plucking is when a bird pulls out its own feathers, either one at a time or in big chunks. It can be caused by lots of different things, like stress or boredom.
You know how sometimes you might bite your nails or pick at a scab? It's kind of like that for birds, but instead of biting or picking, they are pulling out their own feathers. Sometimes they might do it because their skin is itchy or irritated, but other times it's just a habit they develop because they don't have anything else to do.
Feather-plucking is not good for birds because it can leave them with bald patches and can even cause infections or other health problems. It's important for bird owners to make sure their birds have lots of things to keep them busy and happy, like toys to play with and things to chew on. That way they are less likely to start plucking their feathers.
If you notice your bird plucking out its feathers, it's important to take it to the vet to make sure there isn't an underlying health problem causing it. The vet can also give you tips on how to help your bird stop the feather-plucking habit.