Do your hives have a lot of bees hanging near the entrance? This is a common behavior observed by beekeepers in the summer, especially in July when it is hot and the nectar flow has slowed down.
It is often called bearding and, when observed in July, should not be considered a precursor to swarming. If you are seeing this in your hives and are concerned that they are getting ready to move to a new location, calm down and take a deep breathe. Swarming is not imminent.
I liken bearding to a human behavior from the days before air conditioning was common. It’s a sweltering Sunday afternoon, your chores are done, and the inside of the house feels like an oven. Where would you hang out? Why, on the front porch, of course. Some observations you can make to confirm that the behavior you’re seeing is bearding: fewer bees on the front of the hive in the cooler hours of morning and evening and on rainy days; more bees on the front of stronger hives. Stronger hives mean more bees, more body heat, and less room inside.