
A hippo's mouth is huge, measuring about four feet (1.2 m) from top to bottom when open. That's big enough for a six-year-old kid to fit inside These big mouths make a lot of noise. Hippos can produce a 115-decibel roar that's as loud as a train engine. They also make softer...

A hippo's mouth is huge, measuring about four feet (1.2 m) from top to bottom when open. That's big enough for a six-year-old kid to fit inside These big mouths make a lot of noise. Hippos can produce a 115-decibel roar that's as loud as a train engine. They also make softer...