This summer, all the chickens wanted to roost on the edge on the inner coop. This ledge is about 8 feet off the ground. My largest chicken at the time either fell or got pushed off during the night. From where she fell she also likely hit the ramp to the coop on the way down. It was a hard enough fall she died quickly. A vet confirmed it was impact that killed her. So now during the summer I keep the open top of the inner coop covered with fencing do they can't get up there.