No matter how you do it, you must stop robbing or you may lose your colony. Robbing bees will tear open all the honey cells and clean up every last drop. Fighting between bees will kill many and, once the hive is overpowered, predators such as wasps will move in and kill any remaining bees and brood.
Robbing is most common during a nectar dearth and can often be prevented by restricting the entrance to the hives. This works because the colony has a greater chance of defending a small opening than a large one. With very weak or small colonies, however, even this may not be enough.
How to identify robbing bees
Robbing can be identified in several ways:
- Fighting. Bees will tumble and roll—sometimes on the landing board, sometimes in the air.
- Dead bees may be seen on the landing board or on the ground in front of the hive.
- Robbing bees can often be seen examining all the cracks and seams in a hive, even at the back and sides.
- Robbing bees are often accompanied by wasps.
- Some of the bees in the fray may appear shiny and black. This appearance is created when the bees lose their hair while fighting. Both attackers and defenders may have this appearance.
- Robbing bees are never carrying pollen on their legs.
- Robbing bees often sway from side to side like wasps, waiting for an opportunity to enter the target hive.
- Pieces of wax comb may appear on the landing board.
- Robbing bees are louder than normal bees.
- Because robbing bees are loaded down with honey when they leave the target hive, they often crawl up the wall before they fly away and then dip toward the ground as they take off. This may not be immediately obvious, but if you study them for a while, you can see it.
How to stop the robbers
Once it starts, stopping a robbing frenzy is not easy.
- Smoking will not stop robbing, but it will give you a reprieve while you close up the hive. I get the smoker going well and set it next to the hive while I work.
- Reduce entrances to a very small opening. Some beekeepers stuff grass in the entrance—a technique that keeps out the robbers but allows some airflow. Note: Small openings have pros and cons. A small opening means the guard bees have less of an opening to guard, so they have a better chance of succeeded. However, a small opening funnels the hive smell out of one small place, which tells the robbers exactly where the entrance is. This is less of an issue if you are using screened bottom boards because the hive odor dissipates through the screen as well as the opening.
- If robbing is really intense, you can simply close up the hive opening with hardware cloth or screen in a size the bees cannot get through (#8 or #10 work well).
- A water-saturated towel thrown over the hive confuses the robbers but allows the hive residents to come and go from underneath the towel. Evaporation from the towel keeps the hive cool.
- Install a robbing screen. This device re-routes the hive residents through an alternative entrance while the robbing bees, following the scent of the hive, continue to butt into the screen.
- A wide board, a piece of sheetrock, or a plastic panel placed on the ground so it leans against the front of the hive does a good job of diverting robbers. Bees not familiar with the hive seem reluctant to go into the deep shade caused by the board.
- Some beekeepers spread a commercial product such as Vicks VapoRub at the entrance to the colony. This product contains strong-smelling compounds such as camphor, eucalyptus oil, and menthol that confuse the robber bees.
- Some beekeepers recommend removing the lids from all the hives in the apiary. The theory is that the bees become so busy defending their own hives that they stop robbing other hives. However, if the robber bees are coming from somewhere other than your own apiary, it won’t work. Also, it will do nothing to stop wasps and other predators from entering the hives at will.