I'm sure it's normal, but it's kind of freaking me out the way my chickens behave when I turn their light out at night. They start wimpering like little puppies and crowd into a corner just crawling all over themselves. I didn't know chickens were so afraid of the dark. They're 2 1/2 months old by the way... It's strange, and I feel sorry for them, but I don't want to leave the light on all night.