Why Extra Hive Space Doesn’t Always Stop Swarming

If you’ve kept bees for any length of time, you’ve probably asked or been asked this question:

“How can I stop my bees from swarming?”

A common answer is, “Give them more room so they don’t feel crowded.”
From there, we end up with the statement: “Crowding causes swarming.”
But is it really that simple?

Swarming Isn’t Just About Space

In his excellent book Honeybee Democracy, Dr. Thomas Seeley points out:

“To this day, no one knows what specific stimuli the worker bees are sensing and integrating when they make the critical decision to start the swarming process.”

And honestly, I agree with him. “Crowding causes swarming” just doesn’t tell the whole story.

Seeley notes that swarming is linked to a few conditions, things like high adult bee density, lots of young bees, and growing food stores. But remember: correlation doesn’t equal causation. It’s entirely possible that swarming leads to crowding, or that something else entirely causes both.

Here’s an example:
I’ve seen colonies toss out secondary and even tertiary swarms after the first one, even though by then they’ve lost nearly two-thirds of their adult bees. At that point, they’re not crowded at all yet they still swarm.

That’s your sign that swarming is more complicated than “too many bees in the box.”

Can Playing with Hive Space Help?

Now, since crowding does tend to happen around the same time as swarming, beekeepers have naturally tried to “fix” it by opening up space. Some folks have good results breaking up honey bands above the brood nest, checkerboarding, or spreading the brood nest early in the season. Sometimes it works. Sometimes it doesn’t.

But here’s the kicker: if you want this to work, you have to act before the bees decide to swarm.
Once that decision is made, short of making a split, you’re not likely to stop them.

It’s like trying to stop an avalanche halfway down the mountain, it’s already in motion.

Timing Is Everything

Most of the time, beekeepers who call me about swarms have already missed the window.
“I thought they might swarm, so I gave them another super,” they say, “but they swarmed anyway.”
Or, “My mentor said they were going to swarm, so he added a super but it didn’t help.”

Here’s the truth: if the bees have already begun building swarm cells and there are eggs in them, the countdown clock is running. It takes about 16 days for a virgin queen to emerge, which means the decision was made at least two weeks earlier.

From that point on, the hive is in full swarm-prep mode:

• Queen laying slows down.
• The queen is slimmed down so she can fly.
• Wax glands kick into high gear.
• Workers gorge on honey.
• Scout bees start house-hunting.
• And a good portion of the bees just… hang around the entrance, waiting for the signal.

At that stage, dropping on extra boxes is just wishful thinking.

The Takeaway

If you want to use space manipulation to reduce swarming, do it early before the bees make their decision. Once the gears are turning, there’s no reversing them.

I’m not saying you shouldn’t try. Experimenting with your bees is one of the joys of beekeeping. But go in knowing that swarming is a deeply rooted biological process, and sometimes they’re going to do it no matter what you do.

Plan ahead. Work before they do. And remember when it comes to bees, they usually have the final say.