Although hippos may look slow and docile, they're actually very aggressive, killing more people every year than any other large African animal. So, it would follow that you wouldn't want to swim anywhere near them. That's why when researchers from Yale University and the Cary Institute of Ecosystem Studies wanted to study the effects of hippo dung on water quality in Kenya's Mara River, they sent in three autonomous air boats instead of people. To help those boats blend in, they were dressed up as crocodiles.
Read the full article: Autonomous boats get disguised as crocodiles and used to study hippo poop