Check out this video that shows these crazy siafu ants which can form ant groupings as shown in this video of up to 50,000 ants! These ants are able to kill small animals and are sometimes used by tribal groups here to stitch up people. They hold the ant to the wound and the ant bites on both sides of wound and it is so strong it holds the open wound closed for several days at a time. If the wound reopens, they just have new ants bite the wound to hold it together. Pretty crazy, right?