I went out this morning to check my babies and 2 of them had died in the night I had dropped the level of their heat lamp a little (still well over 2 feet off the ground) last night as it was to get to about 30 degrees and they were lying directly underneath it dead. Are chickens really so sensative that they won't move if they're getting too warm? It's supposed to drop down again tonight and I'm terrified to use the heat lamp... suggestions? The coop is 10'X5' and they're tiny so they have a lot of room.... why didn't they move??