What makes honey bees aggressive?

You’ve managed your honey bee colonies all spring and summer with no problem. Now and then an aggressive guard warned you off, but in general the bees were docile.

All of a sudden, however, the bees are angry. They fly at you. They form a dark cloud above their hive. They bury themselves in your pet’s fur. What gives?

Many aspects of a honey bee colony are cyclic in nature, and aggression is no exception. Honey bees have the ability to be aggressive at any time, but certain things set them off. In the late summer and early fall, more of these conditions exist.

Here are some of the factors that make for aggressive honey bees:

  • Queenlessness is frequently a cause of feisty bees. The bad behavior usually stops as soon as the colony or the beekeeper replaces the queen.
  • A shortage of nectar-producing flowers is called a nectar dearth. The bees can’t find nectar so they often try to steal it from other hives. This begins an aggressive behavior known as robbing.
  • Not only are robbing bees aggressive, but the bees being robbed become aggressive defenders of their stores. This often results in a cloud of bees around a hive, especially in the fall.
  • Look carefully. If robbing is going on, you will see bees fighting with each other at the hive entrance. The ground in front of the hive may be littered with dead honey bees.
  • The fighting bees release an alarm pheromone—an odor that warns other bees of the danger. The alarm pheromone makes other honey bees aggressive—more fighting means more pheromone is released which means more bees join the fray. The situation can escalate quickly.
  • Once the alarm pheromone has aroused the bees, you and your pets and your neighbors are fair game as well.
  • The odor of dead bees and the scent of honey being robbed attract other predators. Before long, wasps and yellow jackets have arrived on the scene to collect both meat and honey. This means more fighting and more alarm pheromone. What a mess.
  • Honey bees and wasps are not the only creatures preparing for winter. Colonies in the fall may be attacked by raccoons, opossums, or skunks. Regular visits by any creature—including a beekeeper—may make honey bees more aggressive.
  • Rainy weather, especially when it comes with heat and high humidity, makes bees cranky as well. During the “dog days of summer” no amount of fanning helps evaporate the nectar or cool the hive.

Of course, other factors can produce an aggressive hive. If the queen was superseded by a queen with more aggressive or Africanized genes, that could be the source of the problem. This is unlikely, however. More often than not aggressive behavior is merely a part of the cyclic nature of honey bee colonies.

Rusty

Comments

Greg
Reply

I totally agree. Here in the Northwest, by the middle of July we begin our blackberry flow. The bees love it and the honey is spectacular (apparently it’s 17% sugar to water in the nectar–very high). Then August rolls around . . . our most beautiful, hot sunny month up here, but there ain’t no forage for the bees. They do tend to get a little mean. There was also a time before summer officially set in, about two weeks when there wasn’t much available, and we experienced the same thing. Right now it’s so close to autumn for us, but the dandelions are coming on strong. Our bees are really happy right now, even if winter is about to set in.

Diann
Reply

In Virginia, there are a number of beekeepers who very recently are experiencing something never before seen, or witnessed by long-time beekeepers. The honeybees are fighting with other honeybees (from the same hive) in midair. And we’re seeing many, many dead bees on the ground immediately in front of the hives. Hive robbing was the first suspicion, but has been ruled out as the cause. I am wondering if weather warfare experimentation by the US Govt. may be the root cause. We’ve just had a very peculiar rainstorm, resembling weather/rain manipulation . . . there weren’t dead bees before the rain, only afterward. So perhaps this is an unexpected response to the ELF waves used.

Jim
Reply

The term “aggressive” should never be used in regard to bees of any type.
Honey Bees certainly can be “defensive”, but never “aggressive”.
All types of bees (honey, bumble, others) defend their colony and nest site, but never attack.

Robbing behavior is a sneaky sort of activity, so it is not aggression either.
Robbers may come en masse to a weak or exposed honey store, but individual bees are not interested in a fight, they merely are foraging, and willing to sneak and steal.

“Aggressive defenders”? Try “alert defenders” or “intense defenders”.

Even Africanized bees are merely much more defensive than European Honey bees, and will not attack unprovoked.

Tamara
Reply

Jim, Sorry, but I was just attacked aggressively by one of my honey bees. I wasn’t near the hive, I did nothing to provoke it, it simply flew at me and landed on my head, I remained calm and it stung me. The same thing happened to my husband twice this week. We’re experienced beekeepers and have never had this happen. Until now I would and have said the same thing you did. After this experience, I can’t agree, these bees were aggressive and they did attack.

Brian
Reply

I have to agree with you, Tamara, and disagree with Jim. My wife and I moved into a house about a month ago. The previous owners were beekeepers and had moved the hive about 3 days prior to us moving in. From what I was told, they moved them off to the country. Several bees were left behind. We were aggressively attacked by the bees while trying to move into our house. We finally had to spray the leftover bees as we were told they would die regardless without their queen and hive.

Our new neighbors are also beekeepers and are the ones who got the previous owners of our home into beekeeping. The neighbor was attempting to prepare for harvesting the honey and something obviously set them off. For the past two days I have been aggressively attacked by his bees which are on the very back corner of his property farthest from me. All I was trying to do was water my front yard. I can’t even get out there to mow. The company he has mow his yard had to do it with one hand on the mower and the other hand flailing in the air trying to keep the bees off of them.

My neighbor mentioned that he has never seen them act like this in all of his years of beekeeping. Several of the neighbors have called the city to report my neighbor because they are also being attacked. Fortunately for my wife, our 4-month-old, and myself, all three of his hives are being relocated out to the country. I would assume things will die down once the bees left behind die off. My point being, bees can and do attack aggressively unprovoked as I am living proof. Both myself, the individual who had to endure the bees while installing our cable, and the wife of the beekeeper were all stung by the aggressive bees. The wife was stung multiple times while out on her front sidewalk trying to peek down the driveway at the angered bees a good 130′ or so from the hive. BEE AGRESSIVE B-E-E AGRESSIVE.

Rusty
Reply

Wow, interesting story. I’m going to assume that you are in a part of the country that has been affected by the intense heat. I believe that the nectar dearth caused by the lack of water had a lot to do with the bees being aggressive. Nevertheless, aggressiveness is the one thing that worries me about suburban beekeeping—you never know what will set them off and who will be around when it happens. It is scary.

The only thing I disagree with is that I think you were probably stung by your neighbor’s bees instead of the individuals left behind from the former homeowner. Honey bees defend their home, brood, and honey stores and when that is gone, there is nothing left to defend. Nevertheless, it is a minor issue and not the point here.

I appreciate that you wrote to let us know what happened and, yes, I believe you. Several years ago, after keeping bees year after year with no problem, I suddenly had one hive whose bees would attack anything in sight—including my husband. We ending up re-queening the hive, but I don’t know if that cured it—or if time cured it—but the aggressiveness eventually went away. But for that period of time they were definitely B-e-e Aggressive.

Phillip

“Nevertheless, aggressiveness is the one thing that worries me about suburban beekeeping — you never know what will set them off and who will be around when it happens. It is scary.”

Having recently moved my hives from my urban (slightly suburban) backyard so as to maintain the peace with my neighbours — and to maintain my peace of mind — I have to agree with this one. 98% of the time, my bees were not a problem for anyone. But I’ve seen my bees chase after my neighbours who were nowhere close to the hives. If I had neighbours with small children playing in their kiddie pools, that kind of thing would be a nightmare. Most recently some of my bees got caught in the long hair of one of my neighbours and she freaked out as they buzzed and burrowed into her scalp. Which I can understand. Every day that I kept the bees in my backyard after that was nothing but stress.

I don’t discourage urban or suburban beekeeping. I think it can be done safely under some circumstances. But as with many aspects of beekeeping, urban or backyard beekeeping has been idealized so much that many novices don’t really know what they’re getting into, and neither do their neighbours.

Rusty

Excellent points, Phillip. It’s helpful to hear from people who’ve been there. I know how hard you worked to keep your bees in line but you still ended up moving them, which was the right thing to do. Thanks for writing.

Rusty
Reply

Jim,

Technically, I agree with what you say. Bees are defensive not aggressive. However, the question I am frequently asked–and the one I’m answering here–is “why do honey bees become aggressive?” From the point of view of the person asking the question, the bees appear aggressive. It is a word people use to describe what they are seeing.

When a new beekeeper is being chased by a cloud of bees as he is running from his hive he is the one who feels defensive–and he believes the bees are being aggressive. I can certainly understand that.

Even our legal system has a problem separating defensiveness from aggression. If you are relieved of your wallet by a pickpocket on the streets of New York and you turn around and kill the guy, are being defensive? Or have you crossed the line into aggression?

You can say “aggressor” is an anthropormorphic term, but so is “defender.” I believe it is more important to understand “the why of it” than the name of it. I’ve tried to explain some of the reasons honey bees may behave in this manner–a manner frequently described as “aggressive.” You can call it anything you like.

Mike
Reply

We have several honey bee hives here in east central Florida. We have a combination of wild honey bees (caught while swarming) and some purchased European bees. It is March here and we have just had several swarms. There is plenty of room in the hives and the orange blossoms are in bloom and the bees are producing honey. There seems to be plenty of food. While trying to move a swarm from the swarm hive to a regular hive the bees became very aggressive (even with smoke). It has been 5 hours since the move was made and you still can’t even go within 100 yards of the hives or the bees will chase you relentlessly. One thing I do know is that a killed bee will give off a scent that makes the others aggressive or defensive, whatever term you choose. Even without the bees being riled up we have been attacked and stung when walking about 30 yards away from the hives. I was thinking maybe these bees have become Africanized.

Rusty
Reply

Mike,

Based on your description I would say there is a good chance the bees you caught are Africanized. Normally, a swarm of European honey bees is extremely docile when they are swarming. I have caught swarms a number of times with no protective gear whatsoever. The swarming bees are defending no brood which probably accounts, at least in part, for their docile nature.

Africanized bees, on the other hand, can be quite nasty when swarming and will chase long distances and attack. Since you are right in the heart of Africanized bee territory, you need to be extremely careful. You should probably destroy this swarm before the drones have a chance to mate with any of your virgin queens and produce more Africanized bees.

Mike
Reply

Rusty:
The swarms appear to originate from our hives, but we can’t be sure. They swarm around our hives and then mass in our orange trees that surround the hives. They are usually in a tree within 10 to 15 yards of our hives. Is there a way to identify Africanized bees? If we need to destroy the bees, what is the best method, so as not to damage the hives and foundations. We have also ordered three new Italian queens and bees that should be here around the middle of May.

Rusty
Reply

Mike,

I honestly don’t like the sound of these bees. They may be trying to rob or usurp (physically take over) your other hives. There is no way to tell if they are Africanized short of sending them to a laboratory.

Whether they are Africanized or not, they sound way too aggressive and I think you should consider destroying them. If you can get close enough too them without endangering yourself, spraying them with soapy water will kill them. Soapy water interferes with their ability to breathe, but the soap leaves no harmful residue on anything.

You need to be careful, though. This is not going to make them happy and it may take a few minutes or longer to work, depending how well you can soak them. Take careful precautions to protect yourself and others in the area.

Also, let me know what happens. You’re making me anxious!

Mike
Reply

Thanks Rusty:
I may try to take one down to the Ag Center run by the University of Florida before destroying them. See what they can tell me.

Donna K
Reply

We caught a swarm about 2 weeks ago that just seem to be really nasty. We can’t even fill the front feeders for them without them defending their hive and flying at you. They will continue to chase me back to my yard–even after I’m done working with them. It is a big swarm, and we have 4 other hives that are quite docile. Our boxes are close enough to the yard that I’m concerned that visitors might get stung. I was out in the yard and hours later, one kept flying at my face. I don’t have that problem with the other bees.
Should we keep or get rid of this box?

Rusty
Reply

I wouldn’t think a swarm caught only two weeks ago would be that defensive. By now they have a nest and brood to defend, but to have them chase you is unsettling. I had one hive like that a few years ago. I ended up re-queening the hive and then the problem went away.

I don’t know where you are writing from so I don’t know if Africanized bees are a problem in your area. If not, it may just be the queen’s genetics–some are more aggressive than others.

I think what you do is a matter of how comfortable (or uncomfortable) you are with the neighbor situation. If they keep flying at you long after you’ve worked them, and you’re in an area with other people, I would either get rid of them or re-queen the hive to get rid of those genes. Perhaps you could just destroy the current queen and add a queen cell from one of your other hives.

You will have to wait a while for the re-queening method to work, but it’s a good alternative if you think you can hold out for a few weeks.

Ed Martin
Reply

We recently received packaged bees with a clipped and marked queen. We introduced the bees to their new hive without ever having to use smoke or any protective gear. Then suddenly this week, they have become very defensive to the point we now have to don protective gear even to replace the feeder. Nectar flow is very low right now and we did open the hive long enough to verify the queen is laying. Wow they got extremely defensive. Thinking possibly that they were being attacked by robbers, we have put in the entrance reducer to make it easier for them to defend. We have never had a new hive become this defensive and would appreciate any ideas why this is occuring and what if anything we should do. Fortunatley the hive is somewhat isolated from the house but we can’t even walk within 30 yards of the hive without bees becoming defensive. Please help if you can.

Rusty
Reply

Ed,

It would be normal for bees to be calm during installation since they have no brood or stores to defend, and then to be more aggressive as brood was being raised. That was my first thought anyway. But if they are following you 30 yards out, they are very aggressive indeed.

This is what I would do: Since packaged bees and their caged queen are usually entirely unrelated, I would wait until the queen’s brood starts to take over the hive. The bees that came with the package should all be dead in four to six weeks, and you will be left with only the progeny of the new queen. If all goes well, that progeny will have a more “normal” temperament. I think that will cure the problem if you can hang on for that long.

Let me know how this turn out; I’m curious.

Vickie
Reply

I am a new beekeeper in So Cal. I have two established hives, a hive that has been on my property for over a year from my beekeeper friend that got me interested in these wonderful creatures, and a new hive that I just queened. Everyone has been very kind and docile until I borrowed a brood frame to start my new hive. WOW – not so nice anymore. I’ve had bees chase, bump and sting. I’ve read EHB will subside after about 3-4 hours, but AHB keep it up for days. Four bees even pinned my daughter in the house. Every time she came to the glass doors, they would bee right there buzzing at the glass. I’ve heard they don’t like loud noises. I had a hedge clipper out this weekend and right away 2-3 were in my face. I had to dress in my bee suit to finish my pruning. I did get stung before I put on my suit. Can they tell you’ve been hit?

I had to relocate a hive (at night). How long before they stop swarming the old existing area?

This is a great blog.

Rusty
Reply

Vickie,

It’s funny, but right now this is the most frequent question I’m hearing. And I’ve had the same problem. My own bees, normally as gentle as can be, have been warning me off for two or three weeks, and I get stung just minding my own business.

I can’t tell you for sure why it happens, but I know it happens every year. It may be a combination of things, including fluctuations in nectar sources (or nectar dearths), the change in day length (they just went from getting longer to getting shorter), higher humidity in some areas, a decrease in egg-laying (which occurs after the solstice), an increase in predators such as yellow jackets, an increase in robbing bees (seen more in late summer and fall), and a need to start ejecting drones.

Normally, I just stay clear of the hives until they calm down. It’s just a cyclic thing we have to deal with.

You asked about noise. They don’t like noise, and when they are in this aggressive state, they like it even less. My husband had trouble running the weedeater last weekend, and the lawnmower, even though these normally don’t cause a problem. Bees will swarm around the old hive area for several days after it’s removed. Some of those bees are probably from the colony that was there, and some are probably robbers trying to find the source of the smell. Eventually it will dissipate.

I’m sorry I can’t be more specific. I can only assure you I see it year after year and it does go away. During the other eleven months they will be sweet!

Vickie
Reply

Thank you Rusty. All is calm again. :0) big sigh!

Stephanie Runyon
Reply

I recently discovered that my purple martin house has turned into a honeybee hive. It is approximately 25 30 feet from our house. I am pleased that for the first time in 5 years my garden is doing great…largely due to these little guys. My concern is are they two close to my house?? I love the fact they are around doing their job but I am concerned since I have small children. They are very attracted to our salt water pool and I have seen 10-12 on the railing drinking. We do live in a heavily wooded area and our yard is in the open. Should I have them removed?? I will be sure to do in humanely and in a very environmentally friendly way.

Rusty
Reply

Hi Stephanie,

Honey bees generally do not sting unless they believe their home is threatened. Bees foraging or drinking are pretty benign and tend to mind their own business. It’s interesting they drink from your saltwater pool. Bees need both salt and water, so you’ve made it convenient for them!

Nevertheless, if you are concerned about having them near the house, I recommend calling a local beekeeper. A couple phone calls should locate one. Most beekeepers are happy to have the bees and will remove them for free, especially a colony that isn’t buried in the walls of your home. Don’t call a “pest control” company, as these folks will likely kill them.

Thanks for considering the bees in your decision. And thanks for writing.

Mary
Reply

Rusty

It is August 11 and I just assessed my two bee hives that I’ve had since April 2011. They have done great until now. There was no honey at all in the supers or in the brood box. I feel we are in a nectar dearth here in SC. So, I removed all my supers and started feeding 1:1 sugar water. Later in the day, I noticed the swarming around both hives and dead bees in front of the hives. Should I continue to feed them until the fall nectar flow starts? I’m worried they will starve if I don’t feed them. This is my 1st year beekeeping and it upsets me to think I could lose the hives.

Rusty
Reply

Mary,

What looks like swarming is honey robbing. The dead bees in front of the hive are the result of fighting. When bees attempt to rob another hive of its honey, the bees fight and many will die. Robbing occurs most often during a nectar dearth, so I’m sure that’s what you are seeing.

You should immediately reduce the entrances to one bee length. Maybe 3/4 of an inch or an inch. This will make it easier for the home bees to defend themselves. Also close any other entrances if you have any. You can continue to feed if you do it inside the hive. In other words, use some kind of internal feeder where other bees cannot get to it. Also, do not use any essential oils–just use plain sugar syrup. Bees from all over will smell the essential oils and try to rob that as well.

If you were in that extensive heat wave this summer, it is no wonder the bees didn’t put up much honey. The nectar-producing plants probably didn’t have enough water to supply a good crop of nectar. It was bad luck for many beekeepers. Also, since many hives are going to be short of honey, you can expect to see a lot of robbing.

If your queens weren’t injured and most of the bees are still alive you can probably save your hives if you continue to feed. Cross your fingers for a good fall flow. Keep your entrances small for the rest of the year. You didn’t mention pollen, but if there was no pollen stored you might want to give them a pollen substitute as well. They need pollen to raise young bees and that my be in short supply as well.

Let me know what happens.

Molly Tillotson
Reply

This is a really helpful site. I have had bees for six years and this is the first time I have had a hyper-alert hive for more than a month. I have one (of five) that is and has been really difficult to work this entire season. In every other way they seem OK. I don’t see signs of skunks or coons. I will try interior feeding and perhaps requeen before winter. Thanks a lot for this conversation.

Phillip
Reply

Sorry to be a comment hog (this may be my 3rd or 4th comment today), but a lot of what you outline in the post makes sense. We’re not having a nectar dearth. We’ve had a weird summer with everything growing and blooming about two months later than usual, and I don’t see much robbing going on. But I robbed from the bees yesterday, taking about 3 frames of honey from one of the hives, and the bees went into an instant hissy fit. I should have closed up shop and got out of Dodge instead of hanging out to finish the job without any smoke to disguise my manly musk. For the rest of the day and all of today, those bees have been out to get me. I even saw my next door neighbour getting chased (not good). I’ve never seen the bees so riled up. I won’t do that again. I’m not going near them for the rest of the week. Hopefully they’ll forget about me.

The other factor that could be setting them off is the weather. The “dog days of summer” is exactly what we’re going through. The sky clouded over today but it’s still hot and humid and tomorrow we’re getting buckets of rain on top of it all. Even with a ventilator rim and a screened inner cover, the bees are constantly fanning around the hive entrance. I want to put a screened bottom board on the hive to help them out, but I don’t want to rile them up even more.

Most of the time I love having bees, but at times like this I wonder, “Why am I doing this again?”

Rusty
Reply

Phillip,

I’m not worried about a comment hog, although I would like a picture. I am worried about Kansas. Today I mentioned “we’re not in Kansas any more” and you mentioned getting the h- “out of Dodge.” I wonder if I have any readers in Kansas and if they are offended. I hope I do and they’re not.

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