Since the queen is the source of all worker bees in the colony, it is important that the beekeeper be certain that the queen is the one originally placed in the colony. It is nearly impossible to determine that a specific queen has been lost if the queen has not been given a unique identifying mark.

It is common practice to mark the queen with a small spot of paint on her back (thorax). A color code exists within the beekeeping industry to indicate the year the queen was introduced to the hive.