When to Use a Beehive Entrance Reducer (Essential Tips!)

Your role as a beekeeper is to look out for the best interests of your honey bees. And at various times of the year or in specific situations, you can use an entrance reducer to do this.

Entrance reducers can be used for various reasons at different times of the season. But how do you know when you are being helpful? 

After all… you don’t want to hinder bees and stop them from going about their buzzy business!

So how do you know when to use a beehive entrance reducer?

Keep reading for all the facts about using this handy bit of equipment…

When do you use a reducer in a beehive?

The main reason for reducing the hive entrance is to control traffic flow. But this can also be a way to regulate ventilation and temperature inside the hive. In addition, entrance reduction is necessary when bee colonies are small. For example, when they are newly established or struggling for some other reason.

The hive entrance allows bees to come and go, transporting food to sustain a growing colony. 

Bees actually prefer small entrances!

In his fascinating book “Honeybee Democracy,” Thomas Seeley discovered that bees prefer an entrance of just 2.3 square inches (15 cm²).

Most hive entrances are bigger than this. It allows you to adjust the entry size throughout the season using an entrance reducer (or sometimes nothing at all). 

Smaller entrances are easier to defend against pests and predators. Whereas larger openings improve airflow, affecting internal temperatures and condensation.

Standard wooden reducers for Langstroth hives are designed to fill the entrance snugly. They can be rotated to create small or even smaller access…

Other designs are made out of plastic or metal. This stainless steel version was based on Thomas Steeley’s research and aimed to create the “perfect entrance”!

Should I use a hive entrance reducer? 

Yes, a hive entrance reducer is an important and simple tool. It allows the beekeeper to control events when honey bees need a helping hand.

A honeybee colony is a dynamic organism. The population shrinks in winter and expands in the summer. Bees are relentless in their quest to grow and multiply, but sometimes they struggle. 

Modifying the entrance is one of the ways beekeepers can lend a helping hand.

Let’s look at the different situations where entrance reduction is a helpful tactic…

When to put an entrance reducer on a beehive 

When installing bees from a package or a nuc (nucleus):

The colony is small and vulnerable when installing a new package of bees in a hive. They only have a population of about 10,000 bees. They need to familiarize themselves with their new surroundings, build up their numbers and start drawing out comb. It’s common practice to reduce the entrance so that only one bee can get in or out at a time. (Note: the same applies to the small nuc box itself before installing the bees)

After splitting a colony:

If you perform a split during the swarm season, you’ll have two much smaller colonies. This can make them vulnerable to robbing bees. So close the entrance down to its smallest size.

If you captured a swarm:

If you have managed to capture a swarm, the same rules apply as if you had forced a false swarm by splitting. Keep the entrance small until the colony grows.

When there is robbing:

Robbing can be a severe problem. A colony can lose all its supplies, and many foraging bees could die during the fighting. Robbing typically occurs at the end of summer in August. 

If you know the colony is particularly weak, you can close it entirely for a couple of days. 

Otherwise, reduce the entrance so bees can more easily defend the hive. A small entry will slow down robbers and is easier to guard.

Remember, robbing is better prevented rather than trying to stop it after it becomes a problem. You can do this by installing a robbing screen like this early in the season. (Amazon) They really do help! An alternative is to stuff the entrance with dried grass which the bees will eventually remove themselves. 

When feeding a weak colony:

This might coincide with a robbing problem. If one of your hives becomes weak, especially if there is a nectar dearth (drop-in availability of bee forage), you should reduce the entrance while supporting the colony by feeding. Do this until their numbers build up sufficiently.

In the fall or early winter:

You can put an entrance reducer on hives to prepare for winter, usually around October. When you notice the nectar flow reducing in late fall or early winter, when the temperatures drop below 70°F (21°C), you want to start winter preparations. 

Closing the entrance will prevent cold draughts, rain, and snow, helping keep the colony warm during the cooler months.

To dissuade predators:

If you find your hives are regularly visited by predators like skunks, raccoons, or mice, an entrance reducer will prevent easy access to the honeycomb. A variation of the entrance reducer is also known as “mouse guards.” Mouse guards like this offer better access to the hive, so they can be used during the nectar flow to allow free-flowing traffic and prevent predators. 

Otherwise, a classic entrance reducer does the job. This is also a reason for reducing the entry as bees enter their winter state. Mice will be looking for a warm, comfortable place to nest!

When treating the hive for mites:

Sometimes you have to obstruct the entry for their own good. For example, some beekeepers recommend you close the entrance when treating varroa with essential oils. 

This can improve the efficiency of the treatment.

When to open an entrance reducer on a beehive

When there’s an obvious traffic jam at the entrance, the reducer can be removed. This usually happens around May when the narrowness of the entrance reducer blocks the path of a prospering colony.

A bottleneck of bees at the entrance is a sign that the colony has grown sufficiently large to open up the entrance reducer. A flourishing colony can protect itself much more easily from robbing. 

If a hive is getting congested, you need to open the entrance. 

Opening the entrance also improves ventilation and gives bees the impression of a more open hive. This is important during the swarm season.

When to remove an entrance reducer on a beehive

Unless you live in a particularly hot climate, the entrance reducer isn’t removed until later in the season. In other words, when the population has grown significantly, and there are plentiful amounts of nectar. Weather conditions should also be good to allow bees to fly.

The two main criteria for removing an entrance reducer are:

• A large population
• During a nectar flow

Both of these conditions should be met simultaneously to merit the removal of the reducer. 

Of course, other factors like the ones mentioned above should also be eliminated before removing the entrance guard.

Remove the reducer very carefully and slowly. Note that it can get gummed up with propolis!

Bee hive entrance reducer size

The size of the entrance can vary from one model to another. For example, a standard wooden reducer for Langstroth hives has two notches. This provides two different entry sizes, a small one and a larger one. 

Other styles of reducers can be adjusted. 

Experiment and keep a close eye on bee behavior at the entrance.

Your job is to try and give the bees what they want 🙂