On a casual, walk around inspection last Friday I noticed a bumble bee going in the top of one of my hives. I have had the top cover elevated on the front side to allow a little more ventilation during the brutal heat of the past summer and have not yet let them down. The bumbler landed on the hive body just below the elevated top cover and made its way thru the access hole in the inner cover. I thought that was interesting and wondered what I was going to do if that became a problem. I went on and checked my other 3 hives and then got my veil and went back to the first hive the bumbler was visiting. I was kneeling down looking up into the bottom of the top cover and saw the bumbler rear end at the access hole. I removed the top cover and my bees were pushing the bumbler out. They had killed it and were removing it from the hive. I watched and they finally pushed enough to send him falling to the ground below. I covered them back up and left well enough alone. Anyone ever have bumbler problems ?