Why Did My Bees Leave the Hive? What is NOT a Swarm!
When Swarming Bees Aren't Actually Swarming
Reading Time: 4 minutes
Cartoons and movies give us an (incorrect) idea of what swarming bees look like. So when the time to ask questions came up in my first beekeeping class, I asked, “Why might my bees leave the hive?” Living in a suburban setting on a tenth of an acre, I had unpleasant visions of my bees swarming my neighbors.
I know better now.
But why do bees swarm? For a few reasons, but I’m not going to discuss that here. What I would like to discuss is when you might think your bees are swarming but they aren’t. Specifically, I’ll focus on two scenarios that can set off alarm bells in the mind of a beginning beekeeper.
Depending on the time of year, between 95-100% of a colony is made up of worker bees. These ladies do everything in the hive from feeding the young to housecleaning, to guard duty, to foraging. The job they do is partially dependent on the age of the bee. For example, the first job every new worker has is cleaning duty. They clean out the cell from which they emerged and help clean other brood cells.
As the worker ages, she moves into different roles in the hive. The last job she’ll ever have is a forager, flying near and far to collect resources for the colony.
Just prior to becoming a forager, she’ll walk out the front door, climb up the outside of the hive box, stretch her wings, and take her very first flight. This flight is known as an orientation flight.
As she leaps off the hive, she turns to face it and essentially hovers around the front, perhaps a foot away. She begins buzzing about, side to side, a few inches this way and that. In short order, she’ll back off a bit, still looking at the hive, and begin increasing her altitude. As she does this, she’ll circle around the hive to get a good look at all sides. Higher and higher she’ll climb, always looking down at the hive and its immediate surroundings.
She’s getting a lay of the land imprinting upon her brain what “home” looks like.
Then, as if called back home, she’ll fly back to the entrance and go back inside.
Orientation flights are a normal event in every bee’s life, and during the spring and summer, they happen like clockwork almost every day. But it isn’t just one bee doing this. It’s hundreds or thousands of them all taking their virgin flight together at the same time of day, typically the warmest part of the afternoon.
When you first get your packages, it will be a few days before the queen bee begins laying eggs. Each egg will hatch in 2-3 days into a tiny larva. At day 9, the cell will be capped as each larva begins to pupate. Twelve days later, a new adult bee will emerge. Weeks might pass before she will take her orientation flight along with hundreds or thousands of her sisters.
I distinctly recall the first warm day I saw these orientation flights and thought, “Oh no! Why have my bees left the hive? My bees must be swarming!”
Frantically I called my mentor who chuckled and calmed me down. Why did my bees leave the hive? No bees swarming today. Just happy, healthy bees taking flight for the first time in their lives. It happened again the next day, and the next, and the next, all summer long.
So when you panic and wonder why have my bees left the hive? Consider that they may just be taking orientation flight.
Bees are exceptional thermoregulators. Brood is kept at 90 degrees at all times and, during the winter, the queen is kept at a cozy 60 degrees even when it’s below zero outside.
Sometimes this temperature control is challenging.
In Colorado, where I live, it can get into the low 100s in the summer. It’s not uncommon for us to have multiple days in a row in the 90s. I can see my bees in droves at our pond, collecting water to bring back to the hive for evaporative cooling.
When the days are hot and long, the hive heats up throughout the day. By evening, though the sun is going down, inside the hive is a tenuous balance of temperature control. Just in time for all the foragers to come back home.
Extra bodies in the hive mean extra body heat, which makes thermoregulation even more challenging. Sometimes the challenge is too great and some of the ladies have to be given the boot. With no light to forage by they do what they can — collect on the front porch. My wife and I call this the “Patio Party.”
To the inexperienced beekeeper, this might look like a troubling collection of hundreds or thousands of bees outside, getting ready to swarm. In truth, this is bearding, a normal temperature control behavior of summer bees.
Sometimes the bearding can be quite extensive, with bees piled up on, around, and even hanging from the landing board at the hive’s entrance. The first time I saw my bees bearding my mentor got another frantic call. Again, she chuckled and reassured me. Bearding is NOT swarming.
How do you know if your bees are too hot? There are some things you can do to help your bees maximize their temperature control.
Most of us don’t want our bees to swarm so I understand the concern when we see a behavior that looks like swarming. I’ll leave you with this — the first time I saw a swarm happen in real time I realized how obvious it was. The bees come flying straight out of the hive. They don’t hang out in piles on the entrance, and they don’t intentionally turn around and take a mental image of the hive’s surrounding. They are leaving in droves and they look like it.
That said, I know this summer, I’ll receive frantic calls from my latest beekeeping students. I look forward to chuckling and calming their nerves.