Why are These Yellow Jackets Dying in My Garage?

The Question: I first noticed in my garage that a lot of small bugs that look like small yellowjackets were lying around dead around the windows inside the garage. First I thought that the spiders that live there were catching them, but I’ve never seen these yellowjackets in this area before.

I don’t know where they might be coming from and why they are congregating to die. Now I’m finding them inside my house. Where might they be coming from and why are they all dead? I’m very happy they are not alive and stinging inside my house, but I would like to know what the situation means.

Submitted by: Manuel, Atlanta, GA

The Not So Short Answer: These are almost certainly the Eastern Yellowjacket, Vespula maculifrons, one of our most common yellowjackets, and the smallest yellowjacket (about 0.5 inches, 1.3 cm) in North America. I zoomed in on one part of your photo to show the characteristic shape of the black coloration on the first abdominal segment. According to Sam Droege, a biologist at the Patuxent Wildlife Research Center, this typically takes a “boat anchor shape” in the Eastern Yellow Jacket. The two other common yellowjackets in Georgia would be the introduced German Yellowjacket (Vespula germanica – also called German wasp), which is slightly larger and has more of a diamond shape on the first abdominal segment, and the Southern Yellowjacket (Vespula squamosa), which usually has a connecting line in the first abdominal segment, and has two lengthwise yellow stripes on the thorax.

As to why you have Eastern yellowjackets in your garage, that’s something of a puzzle. Yellowjacket colonies die out each year, with only newly mated queens living over the winter. But September is a little early for a colony in Georgia to be calling it quits for the season. Some yellowjacket species nest readily in houses and garages, but the Eastern Yellowjacket generally doesn’t. They build paper nests in holes excavated underground. Mr. Droege wonders if you have a nest right near your house or garage. “This time of year, the colonies are at their peak but may be running low on available food. They may simply be moving into the house and garage while searching for yummy things (likely there is something that smells attractive in both places).  They then get disoriented and end up trying to get out near the window.

“Inside they won’t sting unless you accidentally sit on one…which can happen as they become weak and may end up crawling on the floor or on a chair or bed. Best bet is to go out in late afternoon when there is a strong sun and take a stroll around the yard.  There should be a parade of yellowjackets going in and out of the nest and the light at that time of day makes them stand out. If you feel you need to get rid of the colony, fill a gallon jug with water add a large amount of dishwashing soap, go out at night, dump it down the hole, put a rock on top and that should do it.  No need for dumping gasoline or poison down the hole during the day, which often just ends up with people getting stung.”

Given gasoline’s potential as a groundwater pollutant, it should never be dumped in the ground, and if you are allergic to bee stings, you should hire a professional to remove the colony, of course, but otherwise, you might just enjoy watching the yellowjackets coming and going, knowing that their days are numbered. And they don’t generally nest in the same place the next year, so whether you destroy the nest or not, they’ll be gone soon. (Although apparently, Southern Yellowjacket queens will sometimes take over an empty Eastern Yellowjacket nest.)

More Information: This question spurred me to look up something I’ve always wondered about: how to tell a bee from a wasp and how to tell a wasp from a hornet. So here’s the story:

Bees – generally plump and furry looking. Their legs usually don’t show when they’re flying. Examples are the familiar honeybees and bumblebees. Their food is nectar from flowers.

Wasps – generally thinner, without the furry look. Usually have two legs dangling when flying. Examples include yellowjackets and paper wasps. Most wasps are predatory or parasitic. Yellowjackets also go for fruit and human food, especially sugary drinks and meat.

Hornets – some species of wasps, usually fairly large ones, are called hornets. Examples include Bald-faced hornet (Dolichovespula maculata – white and black) and the European hornet (Vespa crabro).

The Interesting Science: What do ants have to do with wasps? Well, funny you should ask, because ants are really a type of wasp. As the phylogeny (evolutionary history) below shows, the insect order Hymenoptera includes two Suborders, the Symphyta (sawflies) and the Apocrita (wasps). Within the Apocrita, there are the Parasitica, which includes a vast number of parasitic wasps, and the group of more interest to us right now, the Aculeata. If we go further into the Aculeata we find the Superfamily Apoidea (which includes the familiar honeybee, bumblebee and various bee-like wasps), the Superfamily Chrysidoidea (other wasps), and the Vespoidea. The Vespoidea includes the Family Vespidae, in which we find yellowjackets, paper wasps, and some other common wasps. And also within the Vespoidea is a very important family, the Formicidae – the ants.

So, nested down inside the evolutionary tree of wasps we find all the many species of ants. Traditionally, “wasp” has referred to any member of the Apocrita that is not a bee or an ant. So ants have not been considered to be wasps. That is largely because the original traditions of naming and categorizing animals were not based on evolutionary history (which was unknown at the time). More current conventions try to take evolutionary history into account. You may have heard people say, for example, that dinosaurs are not extinct because birds are really dinosaurs. That’s because if you look at the evolutionary tree of birds, you find that they are nested inside the evolutionary tree of dinosaurs – just the same way that ants are nested within the evolutionary tree of wasps.

Under a system of naming that takes evolutionary history into account, ants would be a variety of wasp – a very successful offshoot of the Vespoidea wasp lineage that includes those yellowjackets.

Hymenoptera Phylogeny

Thanks: My thanks to Sam Droege for his generous help. Mr. Droege is a researcher at the Patuxent Wildlife Research Station, operated by the United States Geological Survey, which despite the “Geological” in its name, is the federal government’s primary agency for wildlife research.

69 thoughts on “Why are These Yellow Jackets Dying in My Garage?”

  1. Hello. I live in Cincinnati Ohio. I recently had a Yellow Jacket nest removed from the wall in my home about a week ago. They were coming in the back of the porch light through the brick wall. He cut a small area of my interior wall and removed it and took the queen and everything, but I’m occasionally still finding dead ones in my kitchen and basement. Is this normal and how long will I see them? I asked him if you got the whole nest and queen again today and he said he did. Are these just stragulars? Do I have another nest?

    Thanks

  2. By the way I think I have the Eastern yellow jacket back with the anchor.
    http://i61.tinypic.com/2u9pzwp.jpg

    [IMG]http://i61.tinypic.com/2u9pzwp.jpg[/IMG]

  3. It seems likely that they are stragglers. And my guess is that without a hive, they will not last long, but I don’t really know how long. Did you ask the exterminator? He might know.

  4. If nothing else, yellow jacket nests go dormant when the weather turns colder, so hopefully, even if the few who are left don’t immediately die, they’ll go dormant and then in the spring, they’ll die or disperse without a queen and a hive. So I’m guessing they won’t be a problem for much longer.

  5. I have noticed a phenomenon for about the last 10 years in the DFW area of Texas. We can go all summer and see few yellow jackets and wasps.
    In fall coming out of summer, we get temps changing from hot , to cool, and mild,back to hot. The temps swing all over from day to day.
    Anyway after the first cold day,the next day The yellow jackets and wasps are out like crazy flying around appearing to find a shelter location for the winter.
    I mean at least 100 flying around my house seperately inspecting each crack and crevis.
    The reason I know they are looking for a place is because they will crawl in the crack around my shed doors. I have opened the shed doors on a cold day to find them lined up in a line from the bottom of one side of the door across the top and down the other side.
    But in the cold they can not move and are sprayed with bug spray. They are trying to over winter.If i had opened the door on a mild or hot day I would be in trouble. Anyway have seen this for many years and i dread the first cold day, because I have to go get a bunch of bug spray that’s not cheap every year. This lasts for about a month,usually beginning in October because that is usually when we get the first cold day. It started today Oct 27.2015.I have never seen any info on the web about this,that is why I am writing this.

  6. Also from Texas, never noticed until recently bought house in rural area just outside of DFW,late summer or fall for 2 years now the yellow jackets seem to get extra invasive and desperately try to get inside structures, house last year, got in through a removed screen in outdoor garage this year, hundreds were visible right before last rain, seem to have diminished some, should I be worried about a nest overwintering in the garage? Scared to go in with spray and attack them…

  7. Ok they seem to have divided into about 7 different nests with about 25 per nest.
    They are the yellow jackets that make paper nests usually under a ledge or something except
    that now they are getting in the small cracks of the eves due to temp change and going in there. They are very invasive to say the least. When it gets warm they come out. If you are in the house you can hear them tapping the window as they think its an opening they can fly into but the glass stops them

  8. Hello there, I live in NYS and just yesterday vacuumed up about 2.5 dozen of what appears to be baby yellow jackets. They are very tiny, no larger than the height of a dime and you can distinctly see the black and yellow stripes. I found about 10 dead in my bedroom windowsill and over 20 dead in the hallway on the floor. There was on large bee (unsure of which kind) crawling up the hallway window and when I went to grab a show to kill it, it had flown away and disappeared. I bought some RAID Wasp and Bee spray and when I got home sprayed the one bee that was still alive. It was much bigger then all the dead ones on the floor so I’m thinking it may have been the Queen. 95% of the dead yellow jackets were in the upstairs hallway near the window, but I found 2 stragglers in the downstairs living room this morning. Any idea as to why they appeared out of nowhere from one day to the next? And why they were only upstairs? I’m not complaining that they were all dead because I am deathly afraid of anything that fly ands stings but I would like to know if I need to start searching for a nest or colony inside my house.

  9. Hi Jessica, can you take a photo of the tiny dead yellow jackets, with something in the photo to show the scale?

  10. I live in Edmonton ab Canada. at the beginning of oct,we noticed wasps flying into a corner crack outside our home,under the stucco. we tried spraying foam, a few times. now,a few wks later,winter weather is arriving all to soon,but now we have a problem with large, lethargic wasps in my bsmt. a few have made it upstairs. im very allergic, so I found out last yr,and have to carry a epi pen everywhere. anyway I can get them,before they get me??

  11. I would like to hear the response to this. I also live in New York state, western New York to be exact. For the past week I’ve been finding yellow jackets in my house. Some are dead in window sills , others seem to be dying, moving very slowly around light fixtures in hallways and my bathroom specifically. They have been all sizes ranging from small looking almost baby like, to the regular size ones we see flying around outside, to one extremely large one I killed yesterday ( much larger than the rest-scared the hell out of me as I am allergic). I searched my bathroom as that is where I’ve found the most (they’re hanging out above my bathroom mirror where the light fixture is), and behind the light fixture there is a small hole where some electric cords come out of the wall I’m not sure if they’re coming in thru there or what. Around the same time (a week ago) that I started finding them in my house I started noticing them in my basement as well. I’m concerned they may have gotten in a wall thru the basmebt and that is how they’re getting into my bathroom but I’m not positive. The first few days I only found maybe one or two a day. Yesterday morning I woke up to at least 4 in my bathroom including the giant one I killed. I was told since its been getting very cold lately at night they’re prob looking for somewhere warm to come into and if there is a nest it’ll die out but I’m concerned they could possibly survive over winter if they’re inside the wall of the house where it may be warm enough ? I am terrified of them , and have a four year old daughter who has never been stung yet so I have no idea if she’s allergic as I am so I’m worried about that as well. Do I need to call an exterminator or will the cold weather kill them off ? Just last night it reached down into the low 50’s.

  12. My response to BetteAnn and Megan, who both are allergic, is to call an exterminator. It’s entirely possible that you have a nest in or around your house, and though the onset of cold weather might take care of the problem in a couple of months, it might also make it worse in the short term, as the insects come into to the house to die. Given your risk, I would call a local exterminator to at least get an opinion of how they are getting into your house.

  13. I live in CT on the NY line, for the past week have been vacuuming up these smaller than summer size yellow jackets all over the house. No idea where they are entering. Most are dead some are weak and still walking around window sills or other lit areas. This is the time of year where we have quite vast temp extremes from summer like to almost freezing. Can’t see any obvious nests outside house or under soffits, etc.

  14. Hi John, can you take a photo of your yellow jackets and email it to tom@askanaturalist.com?

  15. I keep finding wasps (that look like the ones in the OP) around the house. One day we found 5 flying around the upstairs/half moon window above the front door of the house. The next day I found one crawling around in my son’s room (2nd floor), looking like it was close to dying. The next day we found one in our room (second floor), crawling around like it was close to death. A few days later we found one in the 2nd floor bathroom, crawling around like the previous 2. Yesterday there was one flying around by the half moon window. We did not see them all summer. We have checked all the windows (especially the second story windows) and doors for gaps, and have not found any. We have looked around our deck and front porch for nests and not seen any. Where could they be coming from? Also, why would they all be upstairs? I am not allergic but have an intense fear of stinging insects and it is causing anxiety. We live in Kansas City.

  16. Hello,
    About a week ago we have had these German yellow jackets in our bedroom window- we can’t see how they enter. We have been catching the ones alive and releasing them. But there are plenty that are dying in our window also.

  17. Hi Rachel. Did you notice any yellow jacket activity outside your house over the summer? If there is a nest in the wall somewhere, they may already be semi-dormant and so not going outside their nest much. But the occasional individual stumbles into your house through some small crack and can’t find its way back out. Can you email a photo of one of the dead wasps? tom@askanaturalist.com

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