I started my 1st hive April 15th. Everything going great until I cranked up Kubota tractor (25 horse diesel). The 1st time I was 15 feet from hive. Stung twice (deserved that one). Now, every time I start tractor, bees get cranky. I was stung yesterday 75 feet from hive. Today, bees excited when tractor 200 feet from hive with house between tractor and hive. I am concerned about neighbors mowing their yard. I am going to have to mow with bee gear on? Aggressive bees or normal behavior?