Acrobat Ants Dismembering a Grasshopper

2011 October 15

On August 4, 2011 we were all out walking on the trail across our yard when we saw a dead grasshopper on the ground. It was completely covered with crawling black specks, which turned out to be these:

Those tiny black ants were only about 2 mm long. That’s not leaves and grass stems in the background – that’s the grasshopper’s legs, wings, and the tip of its abdomen. They are Acrobat Ants, genus Crematogaster, which are easy to identify from their characteristic heart-shaped abdomen, which is attached to the waist in such a way that they can flip it up over their heads to point forwards.

They also have a couple of spines on the thorax that look to be characteristic, but are hard to see without a lot of magnification:

This is the third ant species listed on Alex Wild’s Urban Ants of the Midwestern United States. They obviously eat other insects when they can get them, but I’m not sure if they just found this grasshopper dead of other causes, or if they killed it themselves. On the one hand, the grasshopper is a lot bigger, but on the other hand acrobat ants do have a venomous sting that may be helpful to them in bringing down even very large prey (although I understand that they don’t actually sting with the stinger, they just use it as a brush to wipe defensive chemicals onto other insects).

Like the pavement ants and the odorous house ants, acrobat ants often get into houses and make pests of themselves. They like sweets as well as meat, so they are likely to get into a lot of different foods in the house. They apparently like to nest in moist, rotting wood and in slightly damp insulation, so a good approach to keeping them out of the house is just to make sure that everything indoors is dry, with no sweating pipes or water leaks. Which, incidentally, is a good way to keep most other insects from establishing themselves in a house, too.

11 Responses
  1. October 15, 2011

    How do you guys ever get where you’re going? Seems as if there’s always an arthropod beckoning to the camera!

  2. October 16, 2011

    Anne: Ah, but we are also walking with a 6-year-old and a 3-year-old. It’s a wonder that we ever get where we’re going in any case!

  3. Shannon C. permalink
    October 17, 2011

    Your macro photography just continues to blow me away with every new post. Thank you for doing this blog!

  4. October 19, 2011

    Thanks, Shannon!

  5. October 24, 2011

    Dittos on the compliments about your photos!

    Here in San Diego, we’re the Land of Argentinian Ants. They’re everywhere. They don’t like sweets, but they love meat. When I used to get them in my house, I’d leave out a tiny piece of cooked chicken and set a timer for 15 minutes. When the timer went off, I’d come back and find a trail of ants leading to the crack / hole in the door / window where they got it. A small squirt of Raid and the vacuum cleaner wiped out the intruders and formed a barrier to further entry with minimal fuss and chemicals. Sugars never worked for this. They only wanted meat.

  6. October 24, 2011

    Google has been thinking about you.

  7. Della3 permalink
    November 7, 2011

    Mint oil (or mint extract – but it dries faster) at the household entrance points works for the ants in my area. Have you tried it? It’s so much safer. You can use a cotton swab to spread it on each entry and exit point.

    I’ve never seen these ants before, and I’m not especially partial to heart shapes, but the hearts on these ants are quite attractive.

  8. November 7, 2011

    Della3: You may have seen these ants before and not realized it. They are pretty tiny, and while it is possible to see the shape of their abdomens without a magnifying glass, you have to look extremely closely to do it.

  9. November 15, 2011

    More gore! Fewer closeups!
    Just kidding, these are great photos! 🙂

  10. November 15, 2011

    Actually, I was surprised that there wasn’t more gore visible in these, too. There’s just that yellow blob of something that the ant is carrying in Photo #3, which I think is a chunk of some internal organ. While I took a lot of pictures, most of them just didn’t turn out well. What with one thing and another, none of the decent ones showed the body of the grasshopper in focus. The ants were pretty neat eaters, too – I think that they were just tunneling into the body rather than really ripping it asunder.

  11. January 31, 2012

    The grasshopper was most likely dead by then – black ants usually feed on dead insects they find. However, when I once found myself sitting on their home and my legs were covered with ants, I wasn’t so sure about it. And the pics are amazing – I enjoy you blog very much, but I’m so lazy that it’s the first time I took time to comment:)

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