A binary star system swirled in space. On a planet near the blue star, there were very tall aliens with eyes on long stalks that waved in the hydrogen cyanide air. On the planet near the red star, there were very short aliens with eyes in their feet that kept close watch on the sulphur worms that burrowed through the yellow, cake-like ground. They thought sulphur worms were delicious.
They hated each other very much, because the tall aliens frequently tripped over the short aliens, and the short aliens had a close-up view of the tall aliens trodding on their favorite snack. Imagine if a very tall man came into your kitchen, tossed a plate of cookies on the floor, and began to perform a flamenco on them, for the tall aliens moved to and fro via the flamenco.
Needless to say, when a third alien arrived, they arrived into a highly charged political situation.
The new aliens were, surprise surprise, humans. With their eyes in their heads and average height in between that of the two aliens, they were in a perfect position to bridge the eons-old differences between the tall aliens and the short aliens.
And they did, by banning the flamenco and accidentally jettisoning thousands and thousands of gallons of toxic nuclear fuel into the habitats of the sulphur worms.
Only one week after the humans arrived, the short aliens looked up, way up, at the tall aliens, who were for the first time looking down, and their people were united in a true and lasting understanding.
That night, all the humans were murdered in their beds.
The Moral: whether you dance the flamenco non-stop or eat worms, you are still better than a human.