The Beekeeper’s Companion Since 1861
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Honey Bee Biology

A Little Known Fact about Swarms But One That’s Quite Fabulous

- June 1, 2017 - Wyatt A. Mangum - (excerpt)

bait hives

Every Spring I put out my bait hives to catch swarms. Swarm-catching has become the big start of my bee season.

I watch for scout bees coming to my bait hives. The scout bees come from swarms searching for new nest sites. Having numerous bait hives and spending time with them provide more opportunities to encounter rare events.

Here is an intriguing and rare encounter that occurred in the Spring of 2015 at one of my bait hive sites (see Figure 1). About 20 scout bees concentrated on bait hive 71 (see Figure 2). Many of the scouts paid close attention to the hive entrances, which was typical. Some of the scouts were inside the bait hive too. In the darkness, the scout bees learned how I configured my bait hive. The hive was empty except for a couple of attractive old brood combs, and the other top bars had foundation strips guiding the swarm to build straight combs. From all the scout bee activity, the bait hive sputtered out a hum.

Kneeling in front the bait hive, I had stopped photographing to adjust the settings on my camera. After a few moments, when my attention returned to the bait hive–something strange had happened. Most all the scout bees had vanished. Disappeared. Poof! Only a few remained, and then they flew off, as if called. The bait hive was dead silent. Then I felt one of the coolest and strangest sensations in all my beekeeping. The feeling told me one thing for certain.

The swarm cloud was coming.

Within mere minutes, a cloud of bees would arrive in front of the bait hive–right where I was kneeling.

In the tense moments, anticipating the swarm’s arrival, usually I do not know from where the storm of bees will rush in (unless I already have a bearing from the scout bees leaving the bait hive). In normal beekeeping, knowing the arrival direction is not too important because the bees are going into the bait hive no matter from where they arrive. However, this occasion was not “normal” beekeeping. I wanted to film the swarm’s approach from as far out as possible.

A couple of weeks earlier, I had put this bait hive next to an abandoned store. Around the corner of the old store from the bait hives was a large field with woods far off on the other side. In front of the bait hives, the terrain was complicated. There was an adjacent highway, lightly traveled. (That is important to note in case I had to shepherd a flying swarm across a highway and not have the bees disrupted by high-speed traffic.) Beyond the highway were cultivated fields and more woods in the far distance. From the bait hive, the swarm could arrive from any direction.

Like a fast-moving clock hand, rotating round and round, I begin looking for the approaching swarm cloud from all directions, even from overhead. It helps to know what you are looking for. From across a field, an approaching swarm cloud appears as a glistening swirl as sunlight reflects from thousands of bee wings. Or a swarm could arrive by descending from just above the treetops, or from over the store’s roof (coming from the other side of the building). A swarm cloud appears darker when seen from below (with virtually no reflection of sunlight from the bees’ wings).

Sometimes I can determine the direction back to the swarm’s bivouac site by watching the scout bees leaving the bait hive. For bait hive 71, nearby obstacles made this determination difficult. To further complicate matters, scout bees from more than one swarm found bait hive 71, and the bees departed in different directions. I figured three directions were present, which presumably led back to three different swarms. While that evidence for multiple swarms is subject to refutation (because it was difficult to tell the directions), arguing for at least two swarms was much stronger, because I had forensic evidence–dead bodies. Lots of them.

Determining when more than one swarm has found a bait hive is easy if their scout bees fight over the site. Quite a bit of combat occurs at the entrances, already a place of intense scouting. Fighting can also occur inside the bait hive. Part of my mental checklist for bait hives, already being scouted, is to watch for fighting at the entrances, and I check for dead bees under the entrances (see Figure 3).

Several times, I have put out one or two more bait hives by a bait hive after finding scout bees fighting over it, trying to give both swarms a hive (you know, a kind of sharing). The fighting continued. Eventually however, a swarm occupied the disputed bait hive. One of the extra bait hives was also occupied. Without knowing the identity of the bees (and some other technical things), I could not tell if adding more bait hives helped reduce the overall conflict, but it was at least consistent with a reduction, and I caught a second swarm. In addition, when I initially set out more than one bait hive at a site (like in Figure 1), scout bees will sometimes fight over one of the hives. While the bait hives were made up the same, both with two empty combs, etc., on a microenvironmental level, many factors remain to potentially make the hives different to the bees. In Figure 1, I suspect a position effect, meaning the bees most always pick the hive on the left, which they have done for a few years now.

As I searched in a circle for the oncoming swarm, a glance around the corner of the old store revealed the familiar sight. There it was! A swarm cloud advancing across the field. Incredible. The vanishing scouts predicted the arriving swarm within no more than five minutes. The large swarm cloud, its quickness always surprising, seemed to pounce like a cat on me, the mouse. In just moments, I was in a cloud of bees (see Figures 4 and 5).

When observing the “vanishing scout bees,” one must be extremely careful not to disturb their behavior, causing the bees to …