This is equal parts disgusting and hypnotic. We’ve seen hippos using their tails to spray their poop around, but we’ve only seen it on land—and the hippo wasn’t pressed right up against glass. Let’s ...

Like most creatures, hippos do not fancy being followed around by humans as they poop. But a robot boat carefully disguised as a crocodile? Why not. The Mara River in Kenya, home to 4,000 hippos, is ...