This is most likely to happen when you install a package of bees in a brand new, never-been-used hive. I’ve heard people say it’s the smell of new lumber they don’t like, or it’s the glue in plywood, or it’s the odor of paint. But it may just be that the bees are not in love with the place, and they would rather live elsewhere. Technically, they have not swarmed; they have absconded. Swarming is colony reproduction that produces two colonies from one. Absconding means all the bees left in one cohesive group. In other words, it is still only one colony—not two—and it lives somewhere inconvenient for the beekeeper.
The problem is easy to prevent. The package of bees will not leave without their queen, so if the queen can’t leave, the bees will stay and start to build comb. Once the comb-building process has begun—and the hive begins to smell like home—you can release the queen and relax.
To keep the queen home, you can leave her in the queen cage until comb-building is underway or you can use a swarm guard, which is like a queen excluder, across the entrance. Beekeeper Jim Withers pointed out that in Langstroth hives you can also use a regular queen excluder placed just under the lowest brood box. In any case, the queen should be released from her cage as soon as comb appears. Queen excluders need to be removed before any drones emerge.
I had several packages abscond at the prison where I taught beekeeping, all from top-bar hives. Since then, I always sequester the queen if the wood is new, or I install several bars of used brood comb—the darker the better—to start them off. This is the same type of comb you would use in a bait hive. Even though it looks disgusting, it is full of odors the bees find irresistible. Go figure.
But what about those old combs? Shouldn’t old black combs—which may contain pesticide build-up or disease—be rotated out of the hive? Absolutely. I handle this by using combs that are almost ready to retire, but not quite. For example, if you retire combs after four years, use three-year-old combs for baiting a hive or starting a colony on new wood. The following year you can rotate them out of the hives.