In "Leiningen Versus the Ants," what type of ants are attacking?
The attacking ants in "Leiningen Versus the Ants" are Army Ants, although of a larger and more ferocious type than normally encountered. They are described as:
...thumb-long, reddish black, long-legged insects... wherever they encountered bare flesh they bit deeply; a few, bigger than the rest, carried in their hind-quarters a sting which injected a burning and paralyzing venom.
(Stephenson, "Leiningen Versus the Ants," classicshorts.com)
There are more than two hundred species of Army Ant, all of which engage in nomadic and predatory behavior; they travel great distances, attacking and eating animals and foliage, and form living nests at night. The ants attacking Leiningen's plantation are therefore in the nomadic phase of their lifespan, although more directly destructive and hostile than most true Army Ants; additionally, only a few species have stingers.