I have 17 chicks that are 17 days old and when i went to check on them 2 of them were going at it! I spooked them and sent them running around, hoping that the 2 would forget about each other, but within a minute the same 2 found each other and started fighting again! I took the 2 out of their box for a while, when i put them back in, they started again. They are only 17 days old!