I had to place all of my chicks in a box because they keep falling out of the nesting boxes outside. Right now (as I type) there is a chick pulling on its wing... like tugging on it. Could it just be a sign of being crowded or do I need to worry about something else? She/he is getting it's pinfeathers in, so could that be the problem as well? I don't think her/his wing is broken.