Swarming – the bee colony reproduction proces

Bee colonies, like all other organisms, eventually die. This can happen due to diseases, environmental factors, hunger, etc. To prevent these insects from extinction, nature invented swarming.

It is generally accepted that the same number of swarms die as are born, maintaining a balance. Too many bees lead to hunger due to competition, while too few can lead to extinction, which is slowly happening today.

From April to May (with some regional variations in Europe), bees focus on replacing the old generation of wintering worker bees with young spring bees. During this period, colonies may weaken, as the young bees may still be few, and the old ones, after a long winter, are quickly exhausted by the intense work of raising young, collecting spring pollen and nectar, and heating the nest.

The situation changes in mid-May and June. Easily accessible food, stable weather, and large numbers of emerging young bees make the hive crowded. Stored food and drones further reduce the amount of air in the hive, leading to suffocation and the accumulation of carbon dioxide on hot days at the end of May. The resulting unemployment, especially in bad weather and full combs, extends the life of worker bees, leading to even greater crowding.

Bee queen cells…

At this point, the decision is made to create swarm cells (please read about this in the queen section). Bees hastily and with increasing fervor begin to build more of these cells, forcing the queen to lay eggs in them and significantly reducing her food rations. A poorly fed queen loses weight and becomes capable of flight. A heavily laden queen with a full abdomen of eggs and swollen ovaries cannot fly.

On a sunny day or two before the swarming date, scouts are sent out to find a suitable place for the swarm to settle and build combs. Once they find such a place, they call for reinforcements and quickly clean it, preventing any foreign bees from entering. In the absence of hollow trees, which once housed many generations of bees, fierce battles for suitable nesting sites can occur if several families from the area are preparing to swarm.

When a place is prepared and chosen (usually the bee family prepares several at once), on a sunny day around 11 a.m., the entire flying population leaves the mother hive. This phenomenon is accompanied by a strong hum of tens of thousands of wings. The bees pour out of the hive as if something were sweeping or blowing them outside. Usually, the old queen leaves with the swarm, circling with her subjects within a radius of about 20 meters.

The bees circle, not concerned with stinging at all. They are almost always neutral to everything happening around them and carry as much food in their crops as they can. They are very heavy.

After about 10 minutes of circling, the queen lands on a tree branch or other convenient place. Within minutes, the entire mass of bees forms a cluster around her. About a third of the bees detach at this moment and return to the mother hive. Swarms can weigh up to 4 kg and contain 40,000 worker bees along with the queen. If the queen gets lost or fails to leave the hive, the entire swarm quickly returns to the hive they came from. If the swarm leaves successfully, the first young queen that emerges from the queen cell will lead the next swarm, known as the “afterswarm,” in contrast to the “prime swarm” with the old queen.

Swarms can occur multiple times during the season. Some bee breeds can produce swarms with only 1,000 workers containing several young queens before their mating flights. Such small bee families usually do not have a chance to prepare for winter and survive until the next spring under current European conditions.

A hanging swarm remains in place for about half an hour. During this time, frantic scouting flights and recruitment dances occur. Scout groups from different selected locations try to convince the swarm with their dances where to build the nest. When one location is significantly better than the others, bees recruited by dancing scouts intensify the same dance. A majority decision is quickly made, and the swarm departs, with the entire cloud of bees flying to the new site to settle. If the locations are equal or suddenly unavailable, the swarm can hang for several days.

The new bee home is usually within an 800-meter radius of their old home. The bees carry enough food in their crops to sustain them for two to three days without collecting supplies and to focus on building new combs.

Meanwhile, in the mother hive, a young queen is born, who usually stings and kills her younger rivals still in the pupal stage. If the hive is still crowded, the worker bees do not allow the young queen access to her younger royal sisters, and swarming quickly repeats. The afterswarm, third swarm, etc., occur until the hive population is too small for further swarming.

It is important to learn how to count bees in this way to avoid keeping them in overly cramped hives, which would lead to a swarming mood and eventually swarming.

Looking at the numbers, it is clear that restricting the queen to one body provides enough bees for the entire hive. If the queen is allowed to lay eggs throughout the hive, the bees will reach a swarming mood within 1.5 months because they won’t all fit. The queen can be allowed to lay eggs throughout the hive only if significant expansion with additional bodies is planned, or if she is naturally limited by nectar storage over the brood during strong inflows. In a highly expanded hive (>4 bodies), a queen excluder is not needed, as the worker bees naturally limit the queen’s egg-laying with stored food.

Studies have shown that summer bees live 4-6 weeks, and their lifespan is inversely proportional to the distance they fly and the amount of brood they feed. Feeding larvae with royal jelly and intensive foraging shorten bee lifespans. Well-nourished autumn bees, which can no longer forage or feed larvae, can survive over six months, ensuring a good start for the family in the spring.

A bee family must always be treated as a whole – a single organism composed of thousands of small cells (bees) connected by strict hormonal dependence. A solitary bee quickly perishes. The swarm efficiently regulates temperature and humidity in the nest. In winter, the temperature in the center of the winter cluster often exceeds 35°C. In hot weather, bees bring in water, evaporating it in the cells and ventilating the hive to lower the temperature by several degrees. Thermoregulation of combs with brood occurs strictly within 33-34°C. Exceeding 42°C results in mass death of larvae, eggs, and pupae, while dropping below 32°C leads to brood diseases like foulbrood or fungal infections.

Bee swarms and each individual have a defensive instinct that varies among different breeds and lines of bees (similar to dog breeds). Most well-bred lines defend only against significant aggression from humans or other animals and constant provocation. Bees are very sensitive to crushing, killing, and frightening other members of their society. Any actions resulting in the killing of worker bees often trigger a mass defensive response, such as stinging. Therefore, it is essential to handle these insects with caution and respect.