What an entrance reducer does
An entrance reducer is a strip of wood, plastic or metal with one or more notches that narrows the hive entrance. A smaller opening is easier for bees to guard, helps keep out larger pests, and can reduce drafts. Purpose-made reducers are inexpensive, and some beekeepers make their own.
When to use one
New packages, nucs and splits. A small colony has few guards, so a narrow opening gives it a better chance of defending itself.
Weak colonies. The same reasoning applies to any colony that has fewer bees than its box needs.
During robbing or when wasps are active. When nectar is scarce, a smaller entrance helps against robber bees and wasps. See robbing screens for stronger measures and how to recognize robbing.
In autumn, to keep out mice. Mice look for shelter as it gets cold. A reducer or mouse guard keeps them out, usually fitted before cold weather arrives. Timing depends on your region.
In cold weather. A smaller opening reduces drafts and heat loss. Colony needs differ by climate, so follow what experienced local beekeepers do.
When to remove or open up
- When the colony is growing and traffic at the entrance is heavy.
- During a strong nectar flow, when congestion at the entrance can slow foraging.
- In hot weather, when the colony needs airflow.
- When a hive is clearly crowded, with bees bearding at the entrance.
Many beekeepers use the reducer’s different notch sizes, starting with the smallest opening and widening it as the colony grows.
Choosing the opening
Most reducers have a large and a small notch; for actual measurements see hive entrance size. A small notch suits small colonies, robbing pressure and winter. A larger notch suits growing colonies. Turning the reducer can usually close the entrance completely, but that is only appropriate for specific short moves and never for a hive that must breathe.
Cautions
- Do not let the entrance block. In winter, dead bees, snow or debris can clog a small opening. Check it regularly and clear it.
- Keep ventilation in mind. A reduced entrance can raise humidity in a damp hive. See mold in a bee hive for moisture control.
- Watch the traffic. If bees are queuing up or the colony seems stressed, widen the opening.
- A reducer is not a cure. It helps with defense but does not replace strong colonies and good management. See also ants in bee hives and our overview of insects and animals that kill honey bees.
FAQ
Can entrance reducers prevent robbing? They help, particularly when combined with other steps.
Do they affect honey production? An over-small opening during a flow may slow traffic, so open it as the colony grows.
Do they fit all hives? Reducers are made for common hive types, and sizes vary. Some beekeepers make their own to fit.