A fascinating clip from the David Tennant narrated BBC/PBS series Spy in the Wild shows a robotic spy hippopotamus built by John Downer Productions carefully swimming upriver to join a pod of wild hippos in Africa, getting rare up-close footage of the incredibly fierce species.
Hippos spend most of their days submerged in water due to the incredibly hot temperatures. Their eyes, nose and ears are located right at the top of their head which allows them to see and hear whist in the water.
The spy hippo then joined the pod underwater where it was able to capture how the giant animals maintain a symbiotic relationship with tiny barbel fish who clean their skin, wounds, and teeth. The fish get fed and the hippo remains infection-free. Sounds like a good bargain for both.
Hippos spend most of their time beneath the water surface so Spy Hippo joins them to discover dozens of barbel fish surrounding the hippos. Hippos are covered in cuts and scratches from fights. The barbels then feed on the parasites that can invade these cuts.