It's normal for chicks to show up and they are usually not a threat and are mostly ignored by the adults except for an occasional peck, the key is your existing birds need to be adults over a year and the chicks need their own place for a bit.
I move my out as soon as they don't require extra heat. If you wait too long older birds are seen as intruders. I pen them separately within the coop for a week or two so everyone gets a good look than I start letting them mingle with supervision, locking them separately at night until I'm comfortable leaving them free. Some use a panic room with a smaller opening, I have enough room not to need that.
I move my out as soon as they don't require extra heat. If you wait too long older birds are seen as intruders. I pen them separately within the coop for a week or two so everyone gets a good look than I start letting them mingle with supervision, locking them separately at night until I'm comfortable leaving them free. Some use a panic room with a smaller opening, I have enough room not to need that.