Greetings Ann, I manage about 15 to 25 hives here in Greenville, S.C. I would not want to be without my upper entrance holes in the supers. Our main honey flow is in the spring (tulip poplar) and ther are times when I have to put on two supers at a time. The extra hole allows the bees to bring the nectar right to the honey supers instead of having to bring it all the way up from the brrod nest. My hives brought in five supers each, and I run brood chambers with a super used for food storage for the queen. The upper entrances are used as much as the main entrance. The upper holes do have guard bees there to protect them from being robbed. Just try putting your hand over the hole. I have not seen any drawbacks from using the upper entrances. It also helps in ventilation during the winter months. Steve Genta [log in to unmask]