without pictures is impossible to say for sure, but if all the bees coming out of the chicken coop are that size and color etc... Then I would say no they aren't honey bee drones. It's more likely that you have some carpenter bees or Bumbles or some other native bee species that set up shop either in the wall or under the coop somewhere. They do occasionally try to rob honey bees but a strong hive can keep them away pretty easily.