I have 3 different age groups... 6 weeks, 4 weeks and 1.5 weeks. Our coop is almost finished.. well, finished enough to get some chicks in there. My question is, will my 6 week old Isa Browns and Cornish crosses be mean to the 4 week old Barred Rocks, Silver Laced Wyandottes and Silkies? The Isa Browns and Cornish crosses are definitely going into the coop... this weekend! The 4 week olds could potentially stay in their brooder a bit longer... but when the time comes to put them together, do I need to worry about an introduction process? I don't know if it matters all that much at this young of an age. Thanks.