The drone hatches from unfertilized eggs out of drone cells. Their task in the bee colony is to mate with the queen bee. Additionally, drones enhance work in the bee colony and produce part of the heat for heating of the brood. When the drone is 12 days old it is capable of fertilizing the queen bee.
The number of drones in one bee colony varies depending on the circumstances both in the bee colony and in the pasture. There number goes from a few hundred to several thousand. The largest number of drones in the beehive is during the swarming season, a period when honey bees bring the most nectar and pollen from the nature into the beehive. It was once thought that if there had been a lot of drones in the beehive, they must have eaten large quantities of honey. However it has been proved that the drone gets food from the bees. Bees feed them when they are needed in the beehive and restrict them food when they are not.
In the apiary, drones can enter any of the beehives undisturbed, without fear of being killed by guard bees. Drones have well-developed smell glands, so they can smell the queen bee, when it goes out to mate, at a distance as far as 2km. The experiment performed in the USA regarding drone gathering and their mating with queen bees, when their movement was followed by radar, shows that the smell that the queen bee leaves behind while mating can be compared to the exhaust fumes of a jet plane. After mating with the queen bee every drone dies immediately.