1.) Octopus have three hearts and blue blood. Two hearts pump blood to the gills and one to the body.
2.) Bananas are slightly radioactive. They contain potassium-40, a natural radioactive isotope.
3.) A day on Venus is longer than its year. Venus takes more time to rotate once than to orbit the Sun.
4.) Your body has more bacteria than human cells. Most of them actually help you stay healthy.
5.) Sharks existed before trees. Sharks appeared around 400 million years ago, earlier than the first trees.