The signal that matters is charged queen cells along the bottom edges of frames — cells with an egg or larva and royal jelly in them. Empty cups mean nothing. Charged cells mean the colony has committed, and you have roughly a week.
What's the difference between a cup and a cell?
A queen cup is an empty, downward-facing acorn-shaped cell. Healthy colonies build them constantly, all season. Finding cups is not a problem and destroying them accomplishes nothing.
A charged queen cell has something in it — an egg, a larva floating in jelly, or capped and elongated like a peanut. That's a decision, not a possibility.
Where the cells are matters
Cells along the bottom bars and lower edges of frames typically mean swarming. Cells in the middle of the comb face usually mean supersedure — the colony is replacing a failing queen without leaving. Same structure, different intent, very different response from you.
What else suggests they're getting ready?
- Congestion. Every frame covered, no open space, bees bearding heavily at the entrance on mild days.
- A backfilled brood nest. Nectar packed into cells the queen wants to lay in.
- A slimmer queen. They stop feeding her so she can fly.
- Drone brood in quantity. Not decisive on its own, but it's part of the picture.
Why does this happen more in some colonies?
Carniolans in particular build up explosively in spring and will swarm if you don't stay ahead of them. That thrift and speed is exactly what makes them good overwinterers here — it's the same trait, and it cuts both ways.
What can I actually do once I find charged cells?
Adding space alone usually won't stop them at that point. The reliable options are:
- Make a split. Take the queen and some brood and stores into a new box. The original colony raises a new queen and thinks it has swarmed. This is the most dependable answer, and it gives you another colony.
- Cut cells and open the nest — remove cells, add space, break up congestion. Works sometimes, and requires checking every week until the urge passes.
Simply destroying cells and doing nothing else usually just delays them a week.
Is swarming actually that bad?
For honey production, yes — you lose most of the field force right before the flow. For the bees, it's normal reproduction and they're fine.
The northern-specific cost is that a colony which swarms in June has to rebuild population and stores in a season that's already short. That's the real reason to stay ahead of it here.
Questions about any of this? Call or text us at (701) 809-0153. We're always happy to help, even if you didn't get your bees from us.