We have a brooder that's about 4ft by 8ft for our chicks. Well here in the past 2 weeks we keep finding dead birds. The chicks are about 3 months old now and we let them into the run during the day and lock them up at night with a heat lamp since it's getting colder now. We cleaned out all the straw and shavings and replaced with dry bedding. Only other change has been we got some baby ducks that range from 1-2 months old. I can't figure out what is killing these birds!!!! Some of the dead chicks have had quite a few of their feathers picked out so I don't know if that's just the other chicks or if it's possible the ducks are doing the killing. Has anyone had issues with ducks and chickens?