It's been so hot, especially in your neck of the woods, the bees are probably desperate for a food source. The honey flow is going on right now so they are probably in a panic to get honey stored for the winter.
You could try putting out some sugar water for the bees in a separate area to distract them from the chicken feed.
Recipe:
2 ½ quarts water
5 lbs. white granulated sugar
Bring water to a rolling boil then remove from the heat. Add sugar, mixing thoroughly. Do not allow this to remain on the heat as you will caramelize the sugar which will cause your bees to become ill.