Robbing is bees taking stores from another colony. It is one of the fastest-developing and most destructive events in an apiary, and it is largely preventable.

When it starts

Robbing arises when a colony's need overrides normal behaviour:

• The end of a flow. The commonest trigger. Abundance stops abruptly
• Dearth
• A weak colony that cannot defend its entrance
• Spilt syrup or honey
• Comb left in the open
• Inspections that take too long during a dearth

The beekeeper is often the one who starts it.

Recognising it

• Bees flying agitatedly in front of the hive, searching along the walls and lid
• Fighting at the entrance; bees grappling in pairs
• Dead bees on the ground in front of the hive
• Robbers flying out heavy and low
• Wax fragments at the entrance as combs are torn open

Searching along the hive walls rather than flying straight in is the earliest sign.

Stopping it

Once it starts it is hard to stop, and it must be dealt with at once.

• Reduce the entrance to a single bee width
• Cover the hive with a wet cloth; robbers cannot find the entrance
• Fit a robbing screen so the entrance is not directly accessible
• Remove the source: Clear away spilt syrup and exposed comb
• Move the colony if it cannot be stopped

Prevention

• Reduce entrances when the flow ends
• Work quickly during a dearth; do not leave hives open
• Do not leave comb in the open
• Feed inside the hive and in the late afternoon
• Do not spill syrup
• Strengthen or unite weak colonies
• Close a dead colony's hive at once

Why it matters beyond the loss

Robbing does not only cost stores. It is the fastest route by which disease and mites spread through an apiary.

Robbers carry agents from the robbed hive back to their own. A collapsing colony that is robbed distributes its problem across the whole apiary.

This is why closing a dead colony's hive immediately matters so much.