Re: Bees moving to neighbors hive?
I agree with Jack and Frank. And the bees that moved in brought their mites with them. Now is a perfect time to get an OAV treatment done and have it kill almost all the mites in a hive.
You started off great with your treatment program, but should have done another round mid October. As long as the bees are foraging, they are bringing back mites. And if they are robbing out a crashing hive, they could be bringing back a lot!
Thankfully, the bees are smarter than I am. They are doing well, in spite of my efforts to help them.