Bees are especially attracted to leaky hummingbird feeders, so make sure your feeder is working properly. They also favor fermented sugar water, so be sure to change the solution in your feeder every 3 or 4 days...more often in hot weather. Bees seem to prefer hummingbird feeders that hang in direct sunlight, so you might try locating your feeder in a shady location. If this doesn't work, try the decoy method: mix up a concentrated sugar-water solution (2 parts water to 1 part sugar), pour it into a shallow plate, and place it near your hummingbird feeder. Each day, move the plate a little further away from your hummingbird feeder. Remove it entirely after several days.