Beekeeping is full of unexpected events, some rewarding and others more challenging. One issue that every beekeeper should understand is honeybee robbing. You may hear experienced beekeepers refer to “robber bees” and assume they are a special type of honeybee, but they are not. Robber bees are ordinary worker bees that invade another colony to steal its honey. They break open capped honey cells, fill their honey stomachs, and return to their own hive with the stolen food. Understanding why robbing occurs and how to prevent it is essential for protecting your colonies.
Naturally, the resident colony does not surrender its honey without a fight. Guard bees fiercely defend their stores, leading to violent battles between the invading robbers and the hive’s defenders. These conflicts often result in significant losses on both sides. If a colony loses too much honey and too many workers, it may become too weak to survive and eventually abscond from the hive.
Why Does Robbing Happen?
Honeybees are naturally driven to gather and store as much food as possible. They build large reserves of honey to help the colony survive periods when nectar is scarce. Because of this instinct, bees readily exploit any nearby source of honey, including poorly defended hives. Weak colonies with limited guard bees are especially vulnerable to robber attacks.
From a bee’s perspective, robbing is simply another form of foraging. This behavior likely developed because wild colonies often discover abandoned hives that still contain unused honey. Rather than allowing those valuable food stores to go to waste, bees collect the remaining honey and transport it back to their own colony.
When Does Robbing Occur?
Robbing is far more likely during certain times of the year. Colony strength and environmental conditions are the primary factors that determine whether robbing will occur. Colonies weakened by diseases, parasites, or pests often lack the numbers and vigor needed to defend their entrance. Many of their workers may also be deformed or weakened, making them poor defenders against invading bees.
A colony’s strength depends on several factors, including the size of its workforce, the number of active foragers, and its ability to maintain normal hive activities. At the center of this strength is the queen. If she is not laying enough eggs, the worker population gradually declines, leaving fewer bees available to guard the hive and gather food.
Food shortages greatly increase the risk of robbing. During late summer and autumn, nectar sources often become scarce, encouraging bees to search for alternative food supplies. Early spring presents a similar challenge because major nectar flows have not yet begun. Since bees can detect the scent of honey from considerable distances, a weak or poorly protected hive can quickly become an attractive target.
How to Identify Robber Bees
Recognizing that a colony is being robbed is relatively straightforward, although identifying individual robber bees is much more difficult. A hive under attack often experiences a sudden surge in activity, with an unusually high number of bees flying in and out of the entrance. An inexperienced beekeeper may mistake this increased traffic for a thriving colony, only to discover later that the hive has been severely weakened by robbers.
Another common sign is bees crawling over every surface of the hive. Unlike resident bees, robber bees are unfamiliar with the hive’s entrance and search for any possible way inside. They inspect cracks, joints, and small openings where the scent of honey escapes. If they find a suitable gap, they may use it to enter the colony.
Robbing almost always leads to fighting between the invading bees and the resident defenders. These battles typically occur on the landing board or in midair, where bees lock together, tumble, and wrestle. Close observation is often required to notice these confrontations. Bees that have been fighting frequently appear black and shiny because they have lost many of their body hairs. Since both robbers and defenders can look this way, appearance alone cannot determine which side a bee belongs to.
Tips and Hints
- A noticeable increase in dead bees on the landing board or on the ground around the hive is a strong indication that robbing is taking place. Both defenders and invading bees suffer casualties during these battles.
- Dead bees and exposed honey often attract additional pests and predators, including wasps. These insects may arrive alongside the robber bees or shortly afterward, making the situation even more stressful for the colony.
- Robber bees rarely carry pollen on their hind legs because they are focused on stealing honey rather than collecting pollen from flowers. Bees returning with pollen are usually members of the resident colony.
- A hive experiencing robbing is generally much louder than normal due to the intense activity, fighting, and constant movement of bees.
Other Signs
Another reliable indicator of robbing is the flight pattern of bees at the hive entrance. Instead of landing directly and entering the hive, robber bees often hover and sway from side to side while looking for an opportunity to slip past the guards. They may linger near the entrance until they find an opening.
Pieces of beeswax comb scattered on the landing board are another strong sign of robbing. As invading bees tear open capped honey cells to reach the stored honey, fragments of wax often fall onto the landing board or collect on the hive’s bottom board.
Robber bees leave the hive heavily loaded with stolen honey, making them noticeably heavier than normal foragers. Before taking flight, they often crawl up the front wall of the hive to gain extra height. As they launch into the air, they frequently dip downward because of the weight of the honey they are carrying. In contrast, bees leaving on regular foraging flights are much lighter. They usually take off directly from the landing board without climbing the hive or dipping toward the ground.
How to Protect Against Robber Bees
Watching honeybees lose their valuable honey stores to robber bees is frustrating and upsetting for any beekeeper. Fortunately, robbing can often be prevented by incorporating protective measures into your regular hive management practices. These precautions reduce the chances of an attack occurring. Robber bees may come from another colony in the same apiary or from a completely different beekeeper’s hive located nearby.
1. Use an Entrance Reducer
Preventing robbing is much easier than trying to stop an active attack. One of the most effective early measures is reducing the size of the hive entrance, especially when natural food sources begin to decline. A smaller entrance is easier for guard bees to defend, making it more difficult for invading bees to enter. Even weak colonies benefit from having their entrances reduced during periods when robbing risk is high.
2. Be Wary of Italian Bees
Italian honeybees are often associated with a higher tendency to engage in robbing compared with some other honeybee subspecies. Because of this behavior, beekeepers who keep Italian bees usually need to pay closer attention to robbing prevention. This concern also applies to nearby beekeepers whose colonies may be within reach of Italian bees from another apiary. Local beekeeping clubs, associations, and agricultural authorities can help you determine whether Italian bee colonies are being kept in your area.
3. Protect the Queen
A queenless colony is at a much greater risk of being robbed than a colony with a healthy queen. Maintaining a queenright hive is therefore an important part of keeping colonies strong and defensive. The queen produces pheromones that help organize and unify the colony. These chemical signals allow worker bees to recognize members of their own hive and identify unfamiliar bees attempting to enter.
4. Place Feeders Inside the Hive
Feeders are useful tools for supporting colonies during periods of food shortages, but their placement is extremely important. A feeder positioned at the entrance can attract bees from other colonies and even draw the attention of wasps. If those visiting bees discover that the colony is weak, they may begin an attack. During nectar shortages, use internal hive feeders whenever possible. Also take care to avoid spilling sugar syrup when refilling feeders or spilling honey during harvesting. Even small amounts of syrup or honey around the hive can attract robber bees and trigger an attack.
5. Utilize Robbing Screens
Beekeeping equipment manufacturers offer robbing screens designed specifically to prevent hive invasions. These devices make it difficult for robber bees to find and enter the true hive entrance while still allowing resident bees to come and go normally. Robbing screens are especially helpful for protecting weaker colonies that you want to maintain separately rather than combine with stronger colonies.
6. Ensure a Strong Colony
Weak and undersized colonies are the easiest targets for robber bees. When several small colonies are struggling, beekeepers may combine them into one stronger colony that can better defend itself. The queen from one of the colonies can be removed, sold, or used to improve the genetics of another colony. Maintaining strong populations is one of the best long-term defenses against robbing.
Stopping Robber Bees
A robber bee attack is a serious disruption for both bees and beekeepers. If the attack is not stopped quickly, an entire colony can be destroyed. The invading bees may remove nearly all available honey stores, leaving the colony without enough food to survive. Once robbing begins, it usually continues until the targeted hive has been almost completely stripped. Often, one colony starts the attack, and other colonies nearby quickly join in, resulting in the complete loss of the hive’s honey reserves.
Early detection gives you the best chance of limiting damage. If robbing has only recently started, quick action can reduce losses and help protect the colony. Beekeepers who do not keep robbing screens permanently installed should consider having one available for emergencies when signs of robbing appear.
Steps to Stop Robber Bees
1. Use a bee smoker
A smoker will not stop robber bees, but it can help calm and control bees while you work on the affected hive. Bees involved in robbing are already highly agitated and may become more defensive than normal. Always carry a lit smoker when approaching a hive under attack and position it near the hive while carrying out your work.
2. Reduce the hive entrance
Entrance reduction is useful both for preventing and stopping robbing. When a hive is being attacked, a smaller entrance gives resident guard bees a better chance to defend the colony. After reducing the entrance, wait about 20 minutes before completely closing the hive if necessary. This allows foraging bees from the colony enough time to return before the entrance is sealed.
3. Seal the hive if necessary
In severe cases, you may decide to completely close the hive to stop further losses. Any robber bees already inside will eventually be dealt with by the resident colony. Once sealed, the hive must remain inaccessible to outside bees until the robbers lose interest and forget the hive’s location. A fine hardware cloth or screen material can be used to block entry while still allowing airflow. Keep the hive closed for several days until the attack stops.
4. Provide food and water to a sealed colony
A colony that has been closed up must still receive support. Provide water and a food source such as pollen or sugar syrup. Colonies that are sealed without feeding may suffer heavy losses, with many bees dying before the hive can be reopened. For already weakened colonies, losing additional workers can be devastating.
5. Cover the hive with a wet towel
Placing a water-soaked towel over the hive can confuse robber bees and reduce their ability to locate the entrance. Resident bees can still enter and exit from beneath the towel. The evaporation of water from the towel also helps cool the hive during hot weather.
6. Use strong scents to confuse robber bees
Some beekeepers use strong-smelling substances around a hive being robbed to mask its natural scent. Materials such as camphor, eucalyptus oil, menthol, and similar strong odors may interfere with robber bees’ ability to locate the hive. Products such as Vicks Vaporub are sometimes used for this purpose. However, these methods should be applied carefully to avoid causing unnecessary stress to the colony.
7. Open All the Hives
The idea behind opening all the hives in an apiary is based on the belief that confusion can restore order. If you choose this method, remove the lids from all the beehives in the apiary. The attacking bees will quickly realize that their own hive is exposed and may return to protect it instead of continuing to invade other colonies. In theory, this keeps bees focused on defending their own colonies and interrupts the robbing activity. However, this approach comes with serious risks. Fighting between colonies can result in the deaths of many bees, and weaker colonies may become overwhelmed and eventually collapse.
This method should never be used on a weak colony that is not already being robbed. A vulnerable hive may become an easy target if opened unnecessarily. Additionally, opening all the hives will not solve the problem if the robber bees are coming from a colony outside your apiary.
Leaving hives open also exposes colonies to other dangers. Birds and other bee-eating predators may take advantage of exposed honeybees. Because of the risks involved, this technique is generally not recommended for inexperienced beekeepers.
Trapping Robber Bees Using a Robbing Screen
Robbing screens are highly effective tools for protecting hives from invading bees. They do not prevent robber bees from discovering a colony, but they prevent them from successfully entering the hive. The screen works by confusing and trapping the invading bees in an area where they cannot locate the true entrance. A typical robbing screen consists of wood or plastic components, mesh screening, and a solid material that blocks the escape of hive odors. This design helps misdirect robber bees by altering how they follow the scent of the colony.
The structure of a robbing screen creates a false entrance that is different from the actual hive entrance. An opening above the solid barrier allows resident bees to enter and exit normally, while a screened section below allows hive odors to escape. Robber bees follow these scents and attempt to enter through the screen, but they cannot pass through it. As they move around searching for an opening, the scent becomes weaker, causing them to return repeatedly to the screen instead of finding the real entrance. Meanwhile, resident bees quickly learn to use their normal entrance location.
Many robbing screens provide two possible entrances for the colony. Only one entrance should be open at a time. If robber bees discover the active entrance, the beekeeper can close it and open the alternative entrance. The resident bees will adapt and begin using the new route, while the robber bees remain unable to locate the correct entry point. Most robbing screens position the entrance several inches above the hive’s original opening, usually around 5 to 6 inches higher.
Robbing screens are most effective when used before a serious attack begins. Prevention is always better than trying to stop an established robbing event. Installing screens before periods when robbing is likely to occur provides the best protection. It is also wise to install them before honey harvesting, since removing honey can trigger robbing behavior among bees that have lost their stores. Those bees may attempt to take honey from weaker colonies nearby. Robbing screens can remain in place for extended periods, including through winter if needed.
Types of Robbing Screens Available
Beekeepers can choose from many different brands and designs of robbing screens. While they may differ slightly in construction and operation, the best screens share several important qualities. They should be simple to install, easy to remove, and compatible with the beekeeper’s hive system. Some models are designed to fit both 8-frame and 10-frame Langstroth hives and can be secured using pins, clips, or other attachment methods.
Wooden robbing screens can sometimes be difficult to manage. When used with slatted racks, they require accurate alignment with the lowest brood box in a Langstroth hive stack. Their rigid construction may leave gaps along the sides, creating opportunities for robber bees or other pests such as yellow jackets to enter. Plastic robbing screens are often preferred because they provide greater flexibility and reduce the chance of unwanted openings.
Another benefit of robbing screens is their ability to reduce bee drifting. Drifting bees can carry Varroa mites from one colony to another, increasing the risk of infestation. Drone bees are especially known for drifting between colonies because they often move freely between hives and may be accepted even when they are not members of the resident colony.
Recommended Robbing Screens
- Homestead Essentials Premium Bee Hive Robbing Screens
- Toughtimbers 10 Frame Moving and Robbing Screen
Will Robber Bees Kill the Queen?
Although robbing is a natural extension of honeybee foraging behavior, it often leads to intense fighting between colonies. The defending bees attempt to protect their honey stores, while invading bees fight to gain access. These battles can result in large numbers of dead bees from both sides. In some cases, the queen may become caught in the conflict and be killed. However, robber bees do not intentionally target the queen. Their primary goal is to collect honey and nectar from the invaded hive.
After a robbing incident has been stopped, it is important to inspect the hive and confirm that the queen is still alive. A careful inspection should be performed to locate her and ensure the colony remains queenright. If the queen was killed during the attack, discovering the problem early gives you a chance to correct it. A queenless colony may eventually decline, abscond, or fail to survive. Some colonies will attempt to raise a replacement queen by creating emergency or supersedure queen cells, while others may require the beekeeper to introduce a new queen.
Conclusion
Honeybee robbing is one of the most damaging events that can occur in a beekeeping operation. Beekeepers should focus on preventing robbing before it starts and acting quickly when signs of an attack appear. Weak colonies require special attention because they are the most vulnerable to invasion. By making robbing prevention part of regular hive management, beekeepers can reduce losses and maintain healthier colonies. Applying proper techniques and using appropriate equipment will help protect honeybees from robber attacks and preserve the strength of the apiary.