Hi all, can anybody tell me why my bird eater got this bald spot it seems to be getting bigger, i was told its because of stress but i dont know anymore its just getting bigger and i am really worried about this. See attached picture, thanks in advance!

Hi Roedolf

Tarantulas flick of those urticating hairs in self defense and when they want to line their web before a moult for example.
So it's normal and nothing too worry about.