Honeybees tell each other where flowers are by dancing.
A returning forager performs a figure-of-eight waggle dance on the honeycomb. The angle of the dance shows the direction relative to the sun, and the length of the waggle tells the distance.
Why is this true?
Karl von Frisch decoded the dance in the 1940s and later won a Nobel Prize for it. It is one of the few known cases of symbolic communication outside primates.
More facts in this category
More about animals
Animals are the easiest place to find facts that sound invented. Three hearts, blue blood, cube-shaped droppings, a punch fast enough to boil water for an instant — every one of these is ordinary biology to the animal doing it. The collection here leans on well-documented behaviour and anatomy rather than folklore, so each entry comes with a short explanation of why the trick actually works and a source you can read next.