In a battle of wits, humans and rats are way more evenly matched than you'd think. While we obviously have an advantage in overall intelligence, our ability to read situations and make decisions is actually no better than a rat's.

Humans are one of 60,000 species that share a 500 million year old common ancestor. This creature was the ancestor of almost every vertebrate species, but it had a sixth sense that most of its descendants long since lost.

The speed of light is 186,282 miles per second. The speed of sound is 761.2 miles per hour. That takes care of vision and hearing, but what about our other senses? Shouldn't there be a speed of smell?

Birds, bees, and turtles all possess the ability to navigate by the Earth's magnetic field. Humans might actually possess the exact same magnetism-sensing hardware as these other creatures, as a light-sensitive protein taken from the human eye gave flies magnetovision.

Gymnastics is one of the most physically demanding activities imaginable, and you would assume it's a good idea to have complete use of your eyes while performing aerial somersaults. But science never got anywhere by taking assumptions at face value.