Awesome! As Jim said, check for eggs making sure there is a queen.
Just a suggestion: I don't know your set up or know if you are raising new bees, splits, and or queens as of now? If so and this hive is really mean, really aggressive; I am suggesting that you take them to an isolated location, away from other bees, including yours. Far enough away from other bees that the drones which may already be present can't find virgins to breed. Destroy all drone brood to slow down the mean genetic cycle, (you don't want mean drones breeding your gentle natured virgins, in your home yard if you are raising some), or anyone else's for that matter. Change the queen out with a good gentle natured bred queen, and give the hive time to repopulate with a gentle strain of bee. As the mean bees naturally die off. In the meantime they will continue to bring in the honey as long as there is a flow, making for a smooth easy gradual transition to a gentle hive. Congratulations!
Some say drones fly far away to mate, Honeypump has taught us that virgins will and sometimes will mate with drones from the same yard.