could someone please help me ? I had 40 chicks 1 1/2 wks ago now i have 7 left. they were purchased from a hatchery. everyday their is some dying and they have bloody stools. they look fine one day and the next they are standing with their head down and very, very weak. they wont eat or drink. i dont know what to do . do you think they have a disease ? they are kept inside my house in a big tub with heat. thanks !