Swarming is a very real concern for any beekeeper. When bees swarm, they usually divide the colony into a large group and leave to look for a new hive. They do this for several reasons. Luckily, with good hive management and an attentive beekeeper, swarming can be prevented.

When the colony swarms, sometimes it splits in two. The colony that leaves the hive will leave with the old queen, and the colony that stays in the old hive will have to create a new queen to run the show. Sometimes, however, all the bees will leave and you will be left with an empty hive. Below are some common reasons why bees will swarm.

Pic_SwarmInTreeCauses of Swarming

  • The population has grown too large and the hive is too small to accommodate all the bees.
  • There's not enough room to build more honey stores.
  • The temperature is too hot. With higher temperatures, more space is needed for each bee to maintain a cooler temperature.
  • The hive does not have proper ventilation and drainage. If the bees cannot ventilate the hive properly, temperatures rise, and they will likely move out of the hive.
  • High humidity and poor ventilation make the hive unbearable for the bees.
  • Problems with the queen. Sometimes older queens have a tendency to fail to produce enough eggs in times of high honey production of the colony.

Prevent & Control Swarming

  • Always give your bees plenty of room. Bees need room to rear brood, store honey, nectar, and pollen, and produce beeswax. If in doubt, add more room! Too much room is better than not enough, but if you notice bees aren’t moving into their new space, it may be too much. Start by adding one Western Honey Super at a time.
  • When bees are in the process of building up the colony and growing, they should get a good amount of sunlight and warmth. Later on, during the honey flow periods, it may be necessary to shade the hives if you live in a very warm climate.
  • Give your colonies plenty of good ventilation in warmer weather. Take out entrance reducers during hot periods and try staggering the supers so they are not flush on top of each other—this allows more air flow. A screened bottom board can also help airflow through the hive.
  • Maintain good air flow and drainage to the hive at all times. Keep grass trimmed around the hive and place the hive in an area that gets good air flow. Placing your hive on a hive stand can also help the hive stay ventilated.
  • Use young queens if possible. Older queens have a tendency to fail during times of high growth and egg laying.