Driver ants kill prey as large as cows by asphyxiation—crawling in their noses and mouths until they suffocate.
What's blind, comes in a variety of sizes, has jaws big enough to tear through human skin, moves in a river-like horde of millions of related individuals, and has no thumbs? These guys, driver ants. They are the largest single-family societies on earth, and they flow over the ground of their African and Asian habitats like a carnivorous stream. The streams are all females. The first thing male driver ants (known as "sausage ants") try to do in life is escape, but if they are discovered by the females, the workers tear off the male's wings and carry him back to the nest to mate with the queen (who lays 100,000 eggs per day) before being killed.
They will also eat mayonnaise. I don't know what that's all about, but it's not a picture you see every day:
Note to self: do not bring mayo to the rainforest. Ever.