Watching the Bees while my dad's on vacation

Hey guys, First thanks for making a Subreddit about bee's it's nice. So, while my parents are off on vacation, I have been tasked with keeping in charge of 3 hives. Today has been pretty hot, and I think they're just cooling off, but I am concerned the first hive is beginning to swarm. Can someone help me with a visual aid of what a swarm would look like vs, bees trying to cool off? Thanks!