Robbing is often caused by the action or inaction of a beekeeper, although not necessarily the owner of the bees actually doing the robbing. The beekeeper concerned may:
- not have disposed of or protected honey or other material attractive to bees in an appropriate manner
- allowed a colony to die out
- not have protected hives well enough from livestock so that the colony gets knocked over and becomes exposed to foraging bees, or
- not have controlled varroa adequately
In some cases, it may be a feral colony that is robbed, although it can only be guessed how frequently this occurs. A New Zealand survey indicates that although feral colonies occasionally have infections of AFB, generally they do not.
Before varroa became established in New Zealand, the main cause of honey bee colony death was starvation in the spring. This did not usually stimulate robbing however, because it was reasonably uncommon for a colony to die at this time of year with its honey still present. The only other common causes of colony death were queenlessness, AFB and occasionally pesticide poisoning.
However, since the advent of varroa, it is now much more common for colonies to die and be robbed out. This has the potential side-effect of increasing the spread of AFB.
Most robbing of managed colonies is caused by poor beekeeping practices.