Most people are aware that a hippo has a rather impressive yawn, but just how big is it on average? Well, thanks to the way in which their jaws operate, they can open up their mouths to a crazy angle, and coupled with the overall size of the hippo in general, it means that there is a pretty impressive mouth and space to fill.
As a result, some researchers have worked out that, on average, the space is large enough to accommodate a four-foot-tall child, which is pretty amazing when you stop and picture that for a moment.
Now, we just hope that they didn’t try this out by using an actual child to check that they were correct in their assessment.