Adapted from Jim Conrad's
Naturalist Newsletter of June 29, 2007
issued from Sierra Gorda Biosphere Reserve,
QUERÉTARO, MÉXICO

INVASION OF
BIG-BOTTOMED ANTS

The rainy season's first soaking rain came eight days ago. The next morning, last Friday, I walked to town to buy fruit and was amazed by what I saw on all the streets and sidewalks: Millions and millions of dark, amber-colored insects lay dead. A few remained alive but they were so lethargic that they seemed ready to die at any moment. They were the size and shape of wasps but up close they were clearly ants, despite their inch-long wings. You can see some dead ones on the sidewalk next to a floodlight at the cathedral below:

BIG-BOTTOMED ANTS

Ant colonies produce lots of winged male ants to mate with a few winged females. Once mating takes place the females fly off to find ground suitable for tunneling into and starting a new colony, but the males simply die. Therefore, the dead ants in the picture are dead males after the previous night's nuptial flights. You can review the ant life cycle at http://www.ipm.ucdavis.edu/TOOLS/ANTKEY/biolmeta.html.

Apparently the emergence of our ant species' winged males and females is coordinated with the advent of the rainy season, for everyone I spoke to knew about the big, winged ants who emerge with the first rains. Don Gonzalo called them hormigas voladoras, which just means "flying ants," but I also heard them called Tatanrías.

UPDATE: By 2014 I've gained enough experience to identify these as leafcutter ants, Atta mexicana. The heaps seen in Querétaro were of males whose function was to mate with the queen who, once mated, will form a new colony. Maybe a very few queens were mixed in with the drones, who die after their time for sex has passed. Atta mexicana workers, normally seen carrying leaf parts, are much smaller, sterile and wingless. Normally these outbreaks occur after a big rain, often the first really good rain of the rainy season.
Back at my computer an image search using the keywords "flying Mexican ants" immediately turned up a picture of my ant, posted at the ant forum of the What's-That-Bug website (http://www.whatsthatbug.com) by Stefanie here in north-central Mexico. Dave Gracer, who promotes the eating of insects at his entomophagy website at http://www.slshrimp.com/ identified the ant as the genus Atta, or leaf-cutting ant, and said that it was edible. Dave also wrote that in Colombia our ants are called Hormigas Culonas, or "Big-bottomed Ants." You can see in my photo that our ants' abdomens are indeed big and rounded. In fact, judging from the size of the greasy spot they form when run over in the streets I'd say that there's a good bit of food value in each ant.

A search on "Hormigas Culonas" turned up an entire Colombian website just on Big-bottomed Ants. It's at http://www.hormigasculonas.com/english_version.htm.

In pitiable English the producer of that site extols the ants' good taste: "When the towns smell to the toasted ant frangances, it does people in the region say: CULONAS ARE BEING ROASTED!"

People here eat them, too, though not as avidly as once they did. It's funny how often people at first react with a laugh when I mention their edibility, but then later in the conversation offer their own recipe. Consensus seems to be that culonas are best lightly salted, then roasted atop a comal (a flat, metal plate, often an excised metal-barrel head, suspended above a fire). Just spritz with hot-sauce and eat.

Cristina at the Reserve says that the ants stink when they gather in such numbers. The Columbian website author expresses a different opinion about the odor, saying somewhat cryptically, "maiden sex smell that wake up the senses; reminiscence of loving rituals fragrances of any lover that want itself." I think he's saying that this ant also has aphrodisiacal properties.