Flock Background: I have 60+ chickens and 4 ducks. They live in a raised house that is 16x20, fully insulated walls and ceiling, pine shavings for bedding, lights in timers, ample roosts, brand new 10 hole roll out nest boxes,2 large feeders, 2 5 gallon waterers and another feeder with oyster shell/grit. The waterers are dumped and refilled daily and bleached weekly. They also have a large outside run. They were started on Purina Start & Grow and are now on Purina Layena Crumbles. They also get 2-4 flakes of Alfalfa hay per day, have a Purina Flock Block and they get 1-2 scoops of a scratch mix outside each day. All of the birds are between 27 & 31 weeks of age. They were vaccinated for Marek's Disease from the hatchery upon purchase. They are all very active, laying good, seem to eat & drink normal. I have White Leghorns, Brahmas, Cochins, Speckled Sussex, Buttercups, Wyandottes, Rocks, Polish, Black Star, Black Giants, Red Leghorns and Comets. There are also 4 ducks in the house. As ducks do they make a sloppy wet mess around the waterers that has to be cleaned every other day or so. This past Sunday morning when I went in to let them out and put the roosts down on the nesting box I found one of my Black Cochin hens dead. The other chickens had pecked a hole in her. There was no blood though which I thought was weird. I carefully watched everyone that day amd the next couple. No one was acting out of the oridinary. This morning everything was fine with my girls. Then tonight after work I go to the barn to do chores. Some of the girls were still outside and the rest inside...nothing odd. When I went in the house to get the waterers and top off feeders I found one of my black star hens dead. No holes, no blood...just dead. Then as I looked around to check the other girls I found 4 with nasty picked, bloody butts. Several of my white leghorn hens had blood all over their heads along with a few other hens...basically looked like they were the guilty parties to the butt picking. Nothing has changed food, light or snack wise. I am stumped as to why my hens are found dead and what brought on a serious butt picking issue an 8 hr period. I'm always worried about them getting bored so I keep the flock blocks in their house, put alfalfa hay inside and outside (which they LOVE) and put a scratch mix outside for them to pick at. I sprayed all the picked butts with Blue Kote. I did notice on one of the hens I sprayed that she has whitish/tan colored poo on her vent. It was kind of pasty looking. I am worried about my girls and am wondering if the sudden deaths could be Coccidiosis or another disease? Any ideas what would cause them to suddenly die? Any suggestions to prevent further picking? Thank You in advance!!