New Mexico: Them!

2019 February 10

While we were looking for gypsum crystals on December 2, 2018, I first spotted this fairly large, thin, spindly-legged ant. It was about 60 degrees at the time, so the ant was moving reasonably slowly and I could get some decent pictures once I found a pose where I didn’t shade her from the sunlight.



I thought at the time that she was a Harvester Ant, but then Dale spotted a hill of these next ants, which are similarly colored but are a bit stockier, and have much bigger heads with stronger jaws.


There were only a few coming and going, with most of them clearly guarding the nest entrance.



I thought at the time that maybe this was one of the species with clearly distinct castes – the thin ones maybe the foragers that actually bring home food, while the big-headed ones would be the defenders of the nest. But, looking at the pictures more closely and browsing BugGuide, now I think that we have two species here. The big-headed ones look like Rough Harvester Ants, Pogonomyrmex rugosus. The first, thinner one’s long, almond-shaped head doesn’t look much like a harvester ant head, and in fact to find that head shape I have to jump to a different (but somewhat related) genus of ants, Novomessor. In fact, it looks like an excellent match for Novomessor albisetosus.

Harvester ants are, obviously, desert dwellers. Unlike ants that live in moister regions, which are mostly predatory, harvester ants mostly collect and eat various types of seeds. They won’t turn up their noses at live prey, and in fact the Novomessor ant genus focuses more on hunting and scavenging than on seed collection, but they are mostly all about the seeds. This can actually be to the benefit of the plants whose seeds they collect, as they are likely to lose track of some of the seeds in the shallower parts of their nest, and they can sprout and grow. Since these ants are large, easy to collect, and don’t need much water, these are the type of ants that you are most likely to get if you buy one of those ant farms that sends you ants through the mail.

Anyway, these ants were only about a one-hour drive from Alamagordo and the White Sands Test Range. So I think they are both good candidates for the species that got mutated into giants by atomic testing in the movie Them! Specifically, I think the Rough Harvester Ants are a fair match:


7 Responses
  1. Anne Bingham permalink
    February 10, 2019

    Them is also noted for early performances by both James Arness and Fess Parker. They both became BIG, too, because of a variety of atomic radiation known as cathode rays.

  2. Carole permalink
    February 10, 2019

    We have harvester ants here in Florida. I’ve noticed they plug the entrance to their nest at night and leave at least one “guard” outside.

  3. February 11, 2019

    Anne: And then, Arness’ little brother, Peter Graves, went on to star in a much worse giant bug movie, this time with grasshoppers!

  4. February 11, 2019

    Carole: Hopefully, they are able to defend themselves from, say, fire ants that way.

  5. Sandra Eisele permalink
    February 11, 2019

    I wish you hadn’t included that last photo from our vacation, I’d rather forget that part.

  6. Anne Bingham permalink
    February 11, 2019

    Ha! Thanks for the tip! I just checked and found out that Beginning of the End is in Season 5 of Mystery Science Theater 3000. Younger Son has the complete collection…and [I was astounded to learn] Husband owns Them Popcorn-intensive weekend coming up!

  7. March 6, 2019

    Anne for the win!

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