Queen Excluder

Beekeeping

Definition

A flat grid (metal wire or plastic) placed between the brood box and honey supers in a Langstroth hive. The grid spacing allows worker bees to pass through but physically prevents the larger queen from entering the honey supers. This ensures honey supers contain only honey, not brood, simplifying harvest.

How It Works

The queen excluder uses a simple size-based separation principle. Worker bees have thorax widths of approximately 4.0-4.2mm and pass through the excluder's slots (typically 4.1-4.2mm). Queens have thorax widths of approximately 4.5-5.0mm and cannot pass through. This prevents the queen from laying eggs in honey super frames.

Without a queen excluder, the queen may lay eggs in the honey supers, resulting in frames that contain both honey and developing brood. These mixed frames cannot be harvested without destroying developing bees, wasting honey, and creating a management headache.

The Debate

Queen excluders are sometimes called honey excluders because they can slightly reduce honey production by impeding worker bee traffic. Worker bees carrying heavy nectar loads must squeeze through the narrow slots, which slows traffic and may discourage some bees from storing nectar in the supers above.

Proponents argue the slight reduction in honey flow is offset by the convenience of brood-free honey supers. Opponents run without excluders and manage queen movement through other techniques. Both approaches work; the choice is personal management preference.

Frequently Asked Questions

Do I need a queen excluder?

Not strictly necessary, but highly recommended for beginners. Queen excluders guarantee brood-free honey supers, which simplifies harvesting considerably. As you gain experience, you may choose to run without one and manage the queen through other methods.

Metal or plastic queen excluder?

Metal (welded wire) excluders are more durable, maintain precise spacing, and last many years. Plastic excluders are cheaper but can warp in heat, altering slot dimensions. Metal is the better long-term investment.

Where does the queen excluder go in the hive?

Between the top brood box and the first honey super. All brood boxes go below the excluder; all honey supers go above it. The queen stays below with the brood; workers pass through to store honey above.