Another rambunctious end of the day

Several days of week I chaperon kids in either the computer lab or Homework Club after school, which I have been doing more than usual this week since the regular woman who does the computer lab has been out sick. The rule is that the kids can only be in there if they are working on school work, and can use the computers for no other purpose. Occasionally there are a few instances when I notice a kid is playing a game and have to stop him/her, or is talking to a friend, etc., but after a stern warning things are fine again. Also usually, students sit every other computer to avoid distractions, but there were nearly 30 kids today in the lab so that option was not available. As a result, they were much more rowdy than usual. Most of them went back to doing what they were supposed to do after I asked them to, but there were two girls who were completely distracting to others around them and extremely disrespectful toward me. At one point I said the next person who talks will get a referral (ie talking to an administrator, which goes on their permanent record), before knowing if I even had the authority to assign them. And I hate making threats, but I didn't know what else to do to keep the chaos down. I wrote down these two girls names and they kept talking. I couldn't do anything else. After the extended day was over I talked to the activities director about them who said she would talk to them both about revoking their computer privileges. It was only then that she told me I could put a cap on how many people could be in the lab and could kick students out if I needed to. Huh. Wish I had known that before. It was utterly insane in there. There is a definitive reason why class sizes need to be small. Even if those two girls weren't in there distracting everyone, it would have been too crazy. Yet, it is also amazing what a difference just two students can make in the dynamics of a room. Holy shnikies.