I have recently added 6 chickens to my gang and I have noticed that the coop area is soo much more stinky. Before, my silkie and EE never smelled as bad. I figured it was poop when one of the new ones pooped on me and as i was cleaning it I took a whift and whooooo STANK! Is it something in their previous diet? How do I get rid of it out of them and the coop?