Ants can join together and form rafts to escape floods, sometimes including several thousand ants in a single raft. This works because an ant's exoskeleton is slightly water-repellent, so when thousands of them team up, they can float on top of the water without even getting wet, because the ants at the bottom of the raft can push against the water without breaking its surface tension, forming it into a bubble underneath them. Ants can stay in these raft formations for weeks, if necessary.
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