I have a flock of 18 chickens about 3 1/2 months old right now. Every morning I go back an open the coop up and they run out of the coop like water being poured from a glass! (I always give them a plate of fresh veggies) Well, twice now, (2 weeks apart) when I open the door they stop short of exiting and just stand there as if afraid to exit. They seem scared and make little almost peeping noises. Finally if I walk back and look around to see if I am missing anything lurking outside a couple of the friendliest ones come running out and stand right up against my legs - touching my legs. if I walk they walk and follow me around like puppies. The rest won't even come out! They finally come out after a few minutes but the whole flock follows me around. When I go out of the run they run back inside the coop! takes a while like maybe 1/2 hour then they finally come out. How are they sensing a predator or is it something else? Does anyone have any thoughts?