I've noticed over the last couple of weeks my hens keep stomping their roost at night. At first thought they we just annoyed at my being in the coop late at night but I noticed it didn't seem to matter if I was inside or outside the coop they just keep stomping their feet all night long. is this some kind of biting insect they are trying to get rid of and if so is there anything I can to to help them get rid of them. I've looked at their legs and underside but don't see anything. Any thoughts would be appreciated.