Why Are Bees Aggressive In Late Summer (What’s Making Bees Grumpy!)

Most of the time, when you visit your beehive, your buzzy friends will be easy-going. 

But bees can be a bit moody sometimes. And certain seasons of the year more than others!

Bees can show aggressive behavior in late summer, for example. 

But how do you explain why they suddenly seem so hostile? 

What changed? And should you be concerned?

In this article, I’ll explain what’s happening and what actions you should take to avoid agitating your bees…

Why are bees aggressive in late summer?

Bees can appear aggressive in late summer and the fall for several reasons. Difficulties collecting food, weather conditions, and other stresses can cause the colony to become defensive.

When you selected your bees, you chose a race of bees based on several different qualities. One of them was probably “gentleness.”

After all… Who wants a bunch of angry bees greeting them every time you show up!

For example, some of the best bees for beginners are Caucasian and Carniolan bees, known for their gentleness.

But whatever the type of bees, certain circumstances will get them riled up.

Bees are more aggressive at the end of summer. 

The end of summer and the fall is a notorious time for bees to seem more aggressive. The transition from fall to winter is stressful for bees as they prepare for wintertime.

The foraging colony seems to anticipate the upcoming lack of nectar (a nectar dearth). 

Honey bees store nectar and pollen for use as food during times when foraging isn’t possible. As a result, they become agitated because the colony’s survival depends on those stores. 

Inspecting a colony during this time risks upsetting them. After all… They’ve spent long hours building up supplies. When someone comes poking around, they think their bounty is threatened. What would you do?!

Why do bees get aggressive in the fall? 

So why are bees so aggressive in the fall?

The most common reasons why bees become agitated in late summer are as follows:

• Lack of nectar at the end of the flowering season.
• Drought causes a lack of bee forage.
• Hives might be being robbed.
• The population of bees is at its highest, increasing the likelihood of meeting an unhappy bee.
• Hot weather.
• Increased varroa mite infestation.

The lack of nectar at this period of the year is the primary reason why bees get aggressive. This is the season when flowering plants begin to die out. At the same time, the number of bees has built up to its highest levels. So there’s a lot of competition for finding bee forage.

Weather conditions at this time of the year can also influence this event. For example, if you’ve been suffering a drought in your part of the world, flowers and bee forage might be rare. 

With experience, you might be able to tell when a nectar dearth is approaching by the behavior of your bees. For example, you might notice bees revisiting flowers several times in an attempt to get every drop of nectar. And when you visit the hive, they can appear more defensive than usual and peeved about your intrusion.

Because nectar is becoming scarce, there can be an increase in robbing bees. Bees might take advantage of weak colonies if resources are low, and each hive needs to work hard to get ready for the colder climate when foraging has to end. 

As a result, bees become more defensive.

Wasps and hornets also run rife in late summer and autumn, and they can attack hives, robbing honey from the combs. (use a hive entrance reducer at this time of year to help your bees. Wasp traps like this placed around the hives are also common practice with many beekeepers.) Amazon

Remember, if you’re experiencing a sweltering end of the season, this can make bees more aggressive. The bee colonies are ripening honey and stocking up for winter in late summer but with less incoming food. The hot, humid conditions will make bees grouchy!

Varroa mites can also increase in numbers, putting stress on a colony and making them unhealthy. This tends to make them agitated. At this time of year, the bee population has reached its peak, and numbers are actually on the decline. The queen has stopped laying eggs, but varroa mites continue to develop. Lower numbers of brood cells and higher quantities of mites put pressure on the colony’s health.

In general, people also get the impression bees are more aggressive in the fall simply because there are more of them. Therefore, the possibility of an encounter with a grumpy bee is higher!

Larger colonies are also known to be more aggressive (or defensive) than the small colonies at the beginning of the season.

What causes bees to become aggressive?

Bees are not naturally aggressive. However, they can be defensive in certain situations when they feel threatened. 

There are several reasons bees can appear more agitated. 

• The season: fall and late summer.
• The weather: poor weather can upset bees.
• Specific colors: they don’t like dark colors like black and red.
• Odors: strong smells can have an effect on a bee’s attitude
• Vibrations: for example, lawnmowers are known to upset bees.
• The way you react to them: reacting aggressively will make them defensive.

These are only a few reasons for defensive behavior. 

How long do bees stay agitated?

This is a tricky question to answer, but logically, for as long as the causes for aggressive behavior persist. Check the reasons above to try and establish the cause.

Some of the time, aggressive behavior is out of your control. But there are a few things you can do to handle upset bees…

How to deal with aggressive honey bees 

Avoid dark colors and strong scents. These are known to agitate honey bees. 

As a general rule, don’t perform hove inspections when weather conditions are poor.

If bees face a shortage of forage for whatever reason, feed them! 

When carrying out hive inspections, use your smoker correctly. For example, don’t puff them with hot dark smoke! They won’t be happy. Also, wear a clean suit to avoid the scent of alarm pheromone from previous stings.

Check for problems such as mites, robbing bees, or maybe even a queenless hive.

If you’ve noticed that the colony has become progressively more aggressive, it may be time to re-queen the colony. Genetics play a large part in the temperament of the bee colony, and a new queen from a reputed breeder could help.

Be sure to wear your helmet and bee suit at this time of year. It can be tempting to take a quick peek inside your hives to see how the girls are doing, but you take more risks in the fall and autumn.

Do bees sting more in fall?

It’s common to hear more reports of bee stings at the end of the summer and autumn. This is most likely because there are more of them around at this time of the year. The same goes for other stinging insects like wasps and yellow jackets.

Why are there so many bees around in fall?

Bee populations reach their highest levels in the late fall. 

Honey bee colonies increase from a small population of maybe ten thousand to 40 or 60 thousand bees at the end of the season.

What time of year are bees most aggressive?

Honey bees are nonaggressive creatures most of the time. But they become defensive if provoked or put under pressure at any time of the year. So if there is a particular time of year that bees are more agitated, then fall is probably the most commonly experienced season.