I was just out in the chicken coop this morning and I noticed a few spots where there was black poop. I've never noticed this before. My husband has been feeding the chickens the last few days so it could have started yesterday or so. We have a mixed flock of 8 adult red star hens and 6 black star pullets that are about 14 weeks old. Other than what looks like some molting going on, they are all normal looking. They are active and happy. They've been on Flock Raiser for about 2 weeks or so. They have lots of water.