There are alot of things to consider and you need to do your research! I never add new chicks to my exsisting flock until they are fully grown and can protect them selves. I start off at around 3-4 months of age, keeping them in seperate pens...but allowing them to see eachother through fencing, gradually letting them free range all together. It takes time for them all to get the pecking order worked out, but the new ones have to go through it to get established in the flock. It can be done, just takes time and patience! Good luck!
