Our 5 week old chicks were raising cain the other night! From like 8:00 PM until about 10:00 and I had NO idea what was going on. Well finally I couldn't listen to it any longer so I closed up their brooder where no light could get in. This is our brooder (notice the interlocking panels). I closed it all in like it is in the pick and then put two more pannels on the top, they quited down and went to sleep. Who knew that chickens had internal clocks and when those clocks would turn on.