Exactly! That's a basic, common sense response. When I was a kid we were swimming at our resort pool and group of kids from a motel down the road (that had no pool) came over to use our resort's pool. And at first, they were loud & boisterous, but mostly fine. But soon their behavior got dangerous and gross. For example, they were eating and spitting food into the pool! (Why?!?!)
My dad got up, went to the lobby and spoke with management. On his way back he grabbed some snacks from a vending machine and called us out of the pool to come eat the snacks he bought us. A few minutes later, management came out and asked every single party poolside or in the pool to show their room key. Dad had us at the table, so it was easy to see that we were with him when he showed his key. (Because yes, management asked him as well, so as not to tip everyone off as to who "tattled".
) Everyone except for those kids showed their key, and the kids were escorted out.
It was easy & simple & fair. The kids from the motel knew what was coming before the manager even reached them, because they started getting out of the pool and gathering their things. And the pool was busy that day, so the manager probably had a dozen parties or more to ask, not just a few, but they did it, because it was the right way to handle the situation.