I bought a 3 pound package of bees with Queen 4 weeks ago put them in a new hive with new foundation. Checked on them weekly and they were doing good, had some frames filled with honey and was laying, had a good brood pattern. Yesterday they swarmed, they got in the top of a 40 ft Pecan tree. I climbed as high as I could and with a bucket on a pole tried to get them. I got most but in doing I knocked some down, and they went back to the hive. I didn't go through them to see if I had the queen, and I didn't check the hive for queen cells. Have any of you had this to happen, and if so what causes this? Thanks