Writing from Caracas Venezuela to ask what huge ant this one might be. I'm guessing it was between 2.5 - 3 cm long (an inch long or slightly larger), but it's hard to say. I will go back and take more pictures of that hydrant's top nut again, with a ruler next to it, to be able to better estimate how long the ant might have been. Will post that pic also in this album on Picasa no later than this weekend:
It is easily the largest ant I've ever seen in my life. Friends on Facebook are saying it looks more like a wingless wasp than an ant, and I sort of agree. In any case, it was the size of a wasp, and looked really mean, even though it was moving pretty slowly.
Searched for "Largest ants" on Google and came across "Bullet ants," which made me worry whether those can be found in the Jardín Botanic of Caracas, and whether I had placed my hands so near such a dangerous little creature. But the photos I saw didn't look that much like a match, specially the jaws. Then found the "trap jaw ants", and those look much more similar, but apparently those are much smaller, not this big. So not sure at all what I came across.
Your help is appreciated. Great website by the way!
All the best,
What great pictures! You're absolutely right: this is a "trap jaw ant," which in this case belongs to the genus Odontomachus. The one you saw is a little bigger than average because she is a newly mated queen who has just lost her wings (you can tell by the enlarged thoracic segments where her wings would have attached). She is looking for a place to start a new colony.
As you probably noticed, Paraponera clavata, the "bullet ant" has much differently shaped jaws (or mandibles). Believe it or not, they are also bigger than the ant you saw. They tend to prefer more densely-canopied forests. I would be surprised to see one on a fire hydrant, but you definitely have them in Venezuela, so it's good to stay on the lookout.
Even thought it isn't a real "bullet ant," you should still watch out: all Odontomachus have painful stings.
I can't tell what species of Odontomachus yours is, but the most common one in your area is Odontomachus bauri. Odontomachus chelifer is larger, but less common. There are many other species of Odontomachus in your region, though, and without looking at it under the microscope, though, I can't be sure.
I hope this helps!
Jesse Czekanski-Moir & the AntAsk Team