The front door of one of our new hives is a busy place. There are bees fanning, guarding, entering, giving directions, exiting, and just cooling themselves. Sometimes you even catch them house cleaning -- removing dead bees, brood that didn't make it, or other debris.
Today is pretty warm so there are many bees fanning. They do this to keep the hive the proper temperature for brood rearing and to take some of the humidity from the air for honey production. When it gets really hot, they fan to prevent the wax from melting.
We added an onboard waterer to each hive today because the temperatures are predicted to be close to ninety and there is no rain in the forecast for at least ten days. Bees, like all animals, need water. We make it easy to get water because the hive is less stressed that way. Less stress creates healthy colonies that can ward off mites and disease and produce more bees and honey.