In a Honey Bee colony there are 3 castes: queens, workers and drones. The ones you see on flowers are workers, which are sterile females. The queens, of which there is only one or a few, are the reproductive females. The drones are the males. The only function of the males is to mate, which they do when the colony swarms. A clue that Honey Bee workers are female is that they can sting, because the sting apparatus in bees, ants and wasps is part of a modified ovipositor (egg-laying organ).