Sit-and-wait, or ambush, predators take weapon evolution to an even greater extreme. Sabertooths were ambush predators who dropped from the branches of trees to plunge their daggers into the necks of unsuspecting prey. Like piranhas, ambush predators no longer chase after prey to hunt them down. In fact, most of them don't run or swim fast at all. Instead, they lurk motionless, often blending spectacularly with their backgrounds like a hunter in a blind, waiting for prey to come to them. When unlucky edibles happen by, these predators lunge from their hiding places, striking out with a snap of their jaws or a flick of their legs to snatch and incapacitate prey before they even recognize what is happening, much less have time to escape.

Emlen, Douglas J, Animal Weapons_ The Evoluti…, loc. 113