I got my first chicks last monday, and HALF died. So I had them send me replacement chicks and they arrived today.
I was worried about pecking or bullying, mostly because I got a pretty aggressive bunch of chicks the first time.
So I ended up putting the new babies in the brooder with the others, and they were SO quick to learn eating and drinking. I had a little trouble with one of my packing peanut cockerels biting one of my older black stars, but other than that they are all cuddling up and running around together. That is exactly 1 week's difference.
We had two sets of six a week and a half apart, I was a nervous wreck when we introduced the two sets together, but they've done awesome together for the last few weeks, however we also have two hens that are 8-9 weeks, and they did not care for their meeting, but that was an accidental quick meeting when the big girls were let out of their coop before I got the little girls all back in the brooder.
How old are the chicks that you would get and how old are the chicks you would consider putting them in with. Depending on the age difference I may or may not put them together. If you do just keep an eye on them, it should be fine.
I've been slowing putting the little girls with the big girls, getting them used to each other (monitored, of course), and they've been doing well. No one is picking on the other, they're sharing food/water just fine. When do you guys think it would be okay to leave them together for good?
I'd say if they are 2 weeks apart, that'd be fine, and that'd probably be easier than putting them together later, but if you wait much longer than that then the older ones will have an established pecking order so when the new ones are added there will be more pecking and bullying. Also like everyone said, watch for pecking.