When I ordered my day olds from the hatchery I ordered an all female mix, I think they might have slipped in a male. This one is larger at 17 weeks and it has started a very bad behavior of jumping on from behind various obvious girls and grabbing them on the back of the neck with it's beak. When I yell it will let go, but I'm not going to be out there all the time. This is my first flock...is this boy behavior? Any suggestions???