The ants are Eciton burchellii, the mini-lions of Costa Rica’s neotropical forest, ferocious pincer-jawed predators that capture nearly every arthropod in their path. They’re pouring out of a huge temporary nest site known as a bivouac. The nest is made of the bodies of live ants themselves linked to one another by their own limbs, creating a huge, jiggling, thermoregulated sanctuary for the queen and her larvae.
