Why is this Cuckoo Maran being so mean and how best do I get her to behave better toward the Silkies? One of the two 10-day-old Cucoo Marans will go over and peck at a Silkie and force the Silkie to move to a different spot of the brooder. I just introduced the Silkies and the 5 mixed bunch into the same brooder today (they came from 2 different hatcheries). They are not overcrowded or over/under heated and there is no shortage of food or water in their brooder. The Cuckoo Marans is part of a batch of 5 (2 CMs, 1 Barred Rock, and 2 Welsummers) that came from a different hatchery from 4 Silkies and 6 Polish (the Polish are currently in a separate brooder due to space issues). I thought that by introducing the 2 different batches of chicks at such a young age things would go more smoothly. Its not going terrible, theyre not killing each other, but the two batches are staying mostly separate in the brooder area and the younger bigger birds are sometimes going after the funny looking feathers on the Silkies. The Polish that were with the Silkies from day one don't have the same kind of annoying behavior toward the Silkies as the new bigger younger birds do.