Bald-Faced Hornet Nest

2012 April 4

Sandy came back from grouse[1] hunting on October 23, 2011, and said that while she hadn’t seen any grouse, she had found a nice hornet’s nest in the woods to the northwest of the house. So, we all trooped back to find this huge hornets nest. There was no hornet activity, so I sawed off the branch it was attached to with my Leatherman[2], and brought it back to the house for pictures. That’s Sam holding it there, for scale.

From the outside, it just looked like a ball of gray paper. Incidentally, the nest doesn’t just resemble paper. It actually is paper. As in, hornets and paper wasps go out, chew up bits of wood, bring it back to the nest, macerate and moisten it, and extrude it in thin sheets that dries to shape as actual, no-fooling paper (or maybe cardboard). Aside from not being bleached to make it white, it is pretty much identical to the stuff that we humans make.

To see what was inside, I got the bread knife and cut it in half. As I pulled aside the top half, while everybody else watched, we noticed that the nest wasn’t quite dead – there were still a few hornets in it, and some of them were moving sluggishly[3].

Soooo, at that point we decided that we didn’t want to take a chance on any of them warming up enough to wake up, so we put the whole thing into our chest freezer to finish them off. Then we continued with the dissection about five days later.

The structure of the nest was a multilayered ball of gray paper, which was mainly designed to keep off the rain and provide some thermal insulation. Inside that ball there were three tiers of actual brood comb, the paper cells that the wasps laid their eggs in to raise brood.

The two tiers near the top were firmly anchored and ended up being cut in half when I sliced the nest, while the bottom-most tier (Tier 1) was only loosely attached and pulled out as an intact disk.

The cells were quite large, and in the bottoms of them you can see the wastes that accumulated from the multiple generations of wasp larvae that were raised in each one.

From the size of the nest, I immediately suspected that it had been built by Bald-Faced Hornets, Dolichovespula maculata. This was confirmed by examining the bodies that we found inside of it.

Bald-faced hornets are a species of yellowjacket (one of the non-yellow kinds), and are distinguishable from the other black-and-white “yellowjacket” species by their size, and by the fact that the first couple of segments of their abdomens are completely black, with no white striping.

They are mainly predatory, eating caterpillars and the like, although they do occasionally come after fruit juices and sweets (we sometimes see them flying around our hummingbird feeder, dogfighting with the hummingbirds). And their jaws are well-suited to catching and squeezing the juices out of their prey.

They are not only larger than other yellowjackets, they also have significantly bigger nests with more wasps inside, and are very aggressive about defending their nests. The stings are quite painful, too. I was stung by one once, and it was worse than a honeybee sting. In addition to the venom, the sting made a big enough hole in my skin that it actually drew blood, which is something I’ve never seen with any other bee or wasp sting. This is why it was just as well that I was photographing them dead rather than trying it while the nest was still active. Although, I probably could have gotten myself stung even by one of the dead ones if I had been careless, since they seem to have died with their stings extended.

All in all, these are some of the ones that you don’t really want too close to the house, but if they are away from the house you really want to leave them alone.

[1] Ruffed Grouse are fairly common in this area, and are quite tasty if you can manage to shoot one. They are pretty much the only common game birds (aside from ducks and geese) in the area, we have too much snow for pheasants or turkeys to do well. In the spring, we constantly hear the males drumming for mates. They stand on a log or stump, and slap their wings to make a sound that starts slow but then keeps going faster and faster, kind of like

[2] I almost always have my Leatherman Wave with me. Between the knives, the saw, the file, the pliers, the multiple screwdriver tips, the scissors, and the can opener (which I actually mainly use for making holes in plastic or wood), it is just too useful to do without. I use it multiple times per day, whether I’m at home, in the lab, or in my office. Even if it doesn’t have exactly the right tool for the job, it generally has one that is close enough. When I have to travel by air, and so have to leave it behind to keep the TSA happy, I always feel like I’m crippled. But, it turns out that Leatherman has a knifeless multitool that is specifically designed to comply with TSA restrictions! While it is a lot less capable than the one I have, it would certainly be better than nothing, which is what I have on trips now.

[3] Sam was a little annoyed with me for having asked her to hold the thing for pictures, when it turned out that there were some not-quite-dead hornets in it. But since nobody got stung, she forgave me.

7 Responses
  1. April 4, 2012

    Hi Tim,

    1) An excellent post! I’d never known hornet nest detail until now. Very cool to see the thing dissected. It’s also fun to see the level of complex organization built by simple hornet behavior. Examples like that make me very interested in AI research.

    2) I agree with your thoughts and experiences with the Leatherman Wave. I’ve got the same one.

    3) Sam looks less than thrilled. I think I’d be giving you the same look. 🙂

  2. JennyW permalink
    April 4, 2012

    I love the photo of your daughter holding the nest. It’s unfortunate that so many little girls (and big girls!) have a fear or loathing of insects, bugs, etc.

  3. April 4, 2012

    Jenny, there’s no girly fear of insects there – check out this same girl in the first picture in this post. I’m just a friend of the family, but that’s one of my favorite pictures of all time.

  4. Carole permalink
    April 4, 2012

    Enjoyed journeying inside.
    Do you suppose solitary bees make use of those nice tunnels when the nests have been abandoned?

  5. April 5, 2012

    Yes, Sam actually loves playing with insects. The look she’s giving me in the picture is because she was still annoyed about not having been carried on my shoulders during our tramp in the woods (I can only carry one little girl at a time, and Rosie asked first). It wasn’t from being scared of getting stung, because at that point we didn’t know that there were not-quite-dead hornets inside.

    Carole: Normally these nests don’t last too long. Squirrels like to dig inside of them in the fall (to eat leftover larvae and recently-dead wasps) and in the winter (for nesting material). They rarely last long enough for other insects to nest in them, and the wasps don’t try to re-use them either.

  6. the bug geek permalink
    November 5, 2015

    Well, you shouldn’t have killed them. They are like aerial ants, taking away organic trash. Cleaners. And if you don’t have the honeybees, in case they went extinct for some reason… yellowjackets also do pollenating. And besides all that, these may be just “bugs”, but they are not stupid, they realise people’s intentions, very soon, case someone starts swinging at them in the air. And they are mirroring YOUR intentions. And one more. case they land on your hand, they feel your overall mental-emotional state, because of the vibrations coming from your heart thru your skin. Treat the bug like you treat your dog, or cat, and NEVER will you be stung. Even if they crawl on your skin. Well, of course you cannot stroke them. But they are in fact friendly, and not ill tempered like you. IE Of course don’t disturb their nest. but otherwise they don’t bite. It is you, who in your fear killed them.

  7. November 5, 2015

    Bug geek:

    I think you misunderstand the situation. This was an end-of-season nest. All the larvae that were going to mature, had matured. All the young queens that were going to overwinter had vacated to their hibernation sites. The summer workers had long since died in the field. The dozen or so that were left in the nest were the old, dying ones that were going to be dead in a few days anyway. Nothing we did made the slightest difference to the hornet population, because this nest had served its purpose and was abandoned to decay.

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