In my (very new) experience it is darkness and newness that will freak chicks out. Scared behavior is crowding together in a corner or other "sheltered" spot, standing upright, wide eyed and sometimes chirping loudly. Is that what they do?
If so I bet it is the light. I would put them in much earlier and have a light actually in the house, a little flashlight. If the light is only on the outside it'll still be much darker in the coop and the sudden change from light to dark is what they are spooked by. Much better if they are in their house while it's still nice and bright in there and just gradually have it get darker. Or, if you can't put them in early, have a light inside, so they can see and get themselves comfy.
We had the brooder off the kitchen and nothing would freak the chicks out like a sudden change in how we turned off the lights at night. I had to figure out a sequence that was gradual enough for them and stick to it. So glad they are outside now. I lock them in one hour before sunset and they have no problem with the transition to dark at all now.
If so I bet it is the light. I would put them in much earlier and have a light actually in the house, a little flashlight. If the light is only on the outside it'll still be much darker in the coop and the sudden change from light to dark is what they are spooked by. Much better if they are in their house while it's still nice and bright in there and just gradually have it get darker. Or, if you can't put them in early, have a light inside, so they can see and get themselves comfy.
We had the brooder off the kitchen and nothing would freak the chicks out like a sudden change in how we turned off the lights at night. I had to figure out a sequence that was gradual enough for them and stick to it. So glad they are outside now. I lock them in one hour before sunset and they have no problem with the transition to dark at all now.
Last night was much better. I put them in earlier than usual. Since it was early I think they thought I was going to play with them as they ran right over to me.