Rapid beeyard growth is happening in neighbor hood, just not my bees. I noticed several hives two houses down from mine. Called my neighbor and he said, Oh, I did know you had bee. And he had let a commercial beek put bees there. And that the fellow liked the spot so well he was going to set up another yard a cross the road, with another 40 hives, 80 total. They will be from just over a quarter to one half a mile from mine. I am wondering how much more chances of mites and pest and disease my bees will come in contact with. Up till now no one had bees within a mile or so and they were hobbies with 1 hive, a couple of miles farther there was a guy with 2 hives. I usually have 5 to 7 hives.
Your biggest concern will probably be robbing which is where the mites would come from. I recommend you reduce your entrances down to about 2" if the hives are strong.
I have the same problem at my farm. The commercial beeks place hundreds of hives around my property. There are about 64 of them 60 feet from my property. I talked to one of the beeks about not putting them so close. He chuckled and said that if I got up in a plane I would find that I have thousands of hives within 2 miles of my hives. I have lost almost all of the small hives there.