ma, be careful of the treats. A little bit of treats goes a long way, and they tend to throw off the balance in their nutrition. Grower feed, until after they start laying is fine. Many will say to use a bit higher protein feed at times, like when they're molting, etc., or add a little calf-manna. The problem with them is that the source of protein is vegetable, not animal protein, and I find that a little animal protein in their diet works best. Cat food works great for those times. Something else I use is canned Mackerel, when I can get it cheap. Once again, don't over do it on the treats, even the cat food, or mackerel. As Gramma mentioned, eggs (scrambled) are a good source of protein to use too, and usually cheaper, since eggs are normally available to you. I told you she knows her stuff!
You should be picking up your chickens every few days, checking them over. Normally, it doesn't take long to know who is who in a smaller backyard flock when you do this, however, they have leg bands that serve the purpose too. Be careful to check the bands regularly with younger birds that are still growing, so they don't cut off circulation. I prefer the plastic bands that expand, for this reason. Since you don't have that many, you might try nail polish (NOT RED). Paint 1 toenail on one foot, on the first bird, then 2 toenails on the same foot, on the next bird, and 3 toenails on the same foot for the next one, then switch feet, and repeat. That way you will be able to identify them as Left Foot 1, 2, 3, or Right Foot 1, 2, 3.
When you quarantine, you might want to put the entire cage into the sheltered area of the coop for several days. That way they all see each other. After several days, when you are going to be out there with them for awhile, let them out of the cage. A squabble will usually break out. Sometimes it's right away, sometimes it takes around 10 minutes or so. When the squabble breaks out, allow it to continue for a moment, then break it up. Make sure no blood has been drawn. If so, put the quarantined birds back in the cage for another day. You will be the acting rooster, keeping peace in your flock. Sometimes that's all it takes, but sometimes another squabble will start shortly after you break up the first one. Allow it to continue for a moment, then break it up. There does have to be a little bit of a squabble to establish pecking order, but it shouldn't be overly violent, drawing blood, and you should be able to break things up 2 - 3 times, and order established. Pay attention to who the aggressors are. Usually there will be only1 or 2 aggressors. If the aggressors won't settle down, put them in the quarantine cage, and see how things go. Make sure they are all getting along before you leave the coop. If you have to quarantine the aggressors, let them stay in the quarantine cage a couple days, then reintroduce them to the flock in the same way. Yes, some people suggest putting them on the roost at night, with the others. I have reservations about doing that with my BA's.
While some people say they are able to slip a bird or two on the roost at night with the rest of their flock, their birds don't seem to notice, and everything is fine, my BA's tend to notice everything. Any change in their coop, or their routine, and I get an earful from them about it.
There is no slipping something by my BA's that they don't notice. That's why I prefer to be there to ensure peace in my flock when I have to reintroduce a member.