Entrance reducers are barriers placed at the entrance to a beehive that restrict the size of the opening. Although usually made of wood, they also come in metal or plastic.
Many entrance reducers—especially wooden ones—give you a choice of two entrance sizes. Others have just one size. Some of the metal and plastic ones are adjustable.
Beekeepers have many reasons to use entrance reducers, depending on the season. However, you should never use them at the height of a nectar flow. During peak nectar collection, entrance reducers can slow down honey production if the bees need to wait in line to get inside the hive.
- Entrance reducers can protect a weak hive from invasion by robbing honey bees or yellowjackets. A colony with an insufficient number of bees may find it difficult to defend a large opening. A smaller opening gives them a fighting chance.
- In winter, entrance reducers can reduce drafts through the hive, keep snow and rain from entering, and discourage small mammals—such as mice—from entering.
- Entrance reducers can help with mite treatments. Some treatments require reduced airflow through a hive, essentially turning it into a fumigation chamber. Reducing the entrance is one of several steps that allow these treatments to work.
The size of entrance reducers depends on their purpose
The size of the entrance you select will depend on your purpose as well as the strength of the hive. If you use an entrance reducer during the winter months, it is important to place the opening at the top of the reducer rather than at the bottom (see below). This is so that the entrance does not become blocked by the layer of dead bees that frequently accumulates in cold weather.
Do not paint your entrance reducers. I painted mine and used them during the height of yellowjacket season and the bees were not happy. As you can see below, they tried to remove them by chewing. They stripped the paint, rounded the corners, and carved long grooves in the wood. It is obvious now that the entrances were too small for the number of bees in those hives.
It’s a good idea to check on any hives with entrance reducers just to ensure the entrance remains open and your bees can get in and out safely. If you leave entrance reducers on all winter, pull them out every month or so and remove any dead bees that have accumulated behind them.
Before you remove reducers in the spring, make sure your colony is strong enough to defend itself against robbing bees. Sometimes, large robust colonies will rob the smaller colonies if access to small colonies is easy.
Managing entrance reducers is an important step in bee management, although these simple-looking devices can sometimes drive me crazy.
Honey Bee Suite