Ants epitomize the expression “strength in numbers.” They get plenty of credit for their industry, and rightly so. What other animal could earn “hurrahs” simply for marching? They’re tenacious, purposeful, and at times, dangerous. Now, we can add another adjective: buoyant. In a tremendous display of unity and ingenuity, this colony of ants forms a living raft when a rising river threatens to swamp their colony. Braving the open water and hungry fish below, the colony risks its own survival to ensure that of its larvae and queen. It’s a remarkable example of self-sacrifice from an ecological linchpin.