Robbing is when the honeybees from one hive start invading another hive to steal their honey. It is dangerous because, once it is started, it is very difficult to stop until the strong hives have completely robbed out the weaker hives. This destroys weaker colonies but also has the potential of transferring a disease from the weak colonies to every robbing colony. Robbing normally starts when honey is exposed without protection when there is not a nectar flow occurring. It is thus important to be very careful how you handle any honey when there is not an active nectar flow.
Bees involved in robbing are much more aggressive. This is directed toward each other, you working the hives, or your neighbor out mowing his lawn. It is very important then to control robbing in the suburban area of Long Island.
We are entering the late summer when there is a dearth of nectar on Long Island. This is a period when it is easy to get the bees started into robbing. It is very important to keep the beeyard neat and tidy as you work and not expose open honey for any period of time. This can occur as you pull a super and break burr comb filled with honey or as you scrape burr comb in your hive examination. It is very important to gather up your scrapings and keep supers covered as you work the hive. Get the hive put back together as quickly as possible with as little loose honey as possible.
Professionals who must work the bees in a period when robbing is easily started often work with a screen, a box or tent made with screening material to protect the colony being examined. This prevents other colonies from attacking the open hive and its supers. The flight is temporarily interrupted as the returning bees can't get in and the exiting foragers are stopped at the screen.
Another method often used successfully when the colonies are near equal strength is to remove the covers from all of the hives as soon as you start the yard and wait to replace the covers until after you have finished. This works because each hive is then exposed and the bees are busy on defense. This can make the bees more difficult to work but not as bad as when active robbing is taking place. It can also be used to slow down robbing when it has begun.
Robbing can sometimes be stopped by nightfall. The bees are all back home and have a chance to get things cleaned up without disturbance. The next morning, sources from the previous day are explored but the lack of exposed honey diffuses the situation.
Another preventative or curing method is to reduce the entrances on all of your hives to a size that is easily defended by that colony. This may involve entrance reducers or the use of bunches of grass as a temporary block to stop robbing.
When you extract, you have empty wet supers. It is best to put these back on the hives for cleaning. Do not stack them outside and allow the hives to have a free-for-all because it will start robbing and gets bees flying all over looking for more exposed honey, thus frightening your neighbors. Put them on the hives in the evening, only a few at a time. You want them to be able to clean up the free honey as quickly as possible, preferably over night. This means that you need to be careful even in the extracting room to keep stray honey on the inside of the boxes, not on the outside.
Only you can prevent robbing from getting started!!