Tweet this video! - http://clicktotweet.com/xWNms It's mind-blowing to think about the multitude of animals that exist in this world. From the tiny flea to the great blue whale, each animal possesses a unique quality that makes it stand out from the rest. Even if you're a zoology expert, you might be surprised by some of these 25 amazing facts about animals. Prepare to be astounded by the resilience, physical abilities, and sheer brilliance of these magnificent creatures. https://twitter.com/list25 https://www.facebook.com/list25 http://list25.com/ Check out the text version too - http://list25.com/25-amazing-facts-you-didnt-know-about-animals/ Here's a preview: Houseflies don't allow their short lifespans (14 days) to hinder their musical abilities. They always hum in the key of F. Ostriches can run faster than horses, and the male ostriches can roar like lions. Bats are the only mammals that can fly. Kangaroos use their tails for balance, so if you lift a kangaroo's tail off the ground, it can't hop. On average, there are 50,000 spiders per acre in green areas. Tigers not only have stripes on their fur, they also have them on their skin. No two tigers ever have the same stripes. To escape the grip of a crocodile's jaw, push your thumb into its eyeball -- It will let you go instantly. Fleas can jump up to 200 times their height. This is equivalent to a man jumping the Empire State Building in New York. A cat has 32 muscles in each ear. Elephants can smell water up to 3 miles away. They are also one of the three mammals that undergo menopause -- the other two being humpback whales and human females. Koala bears almost exclusively eat only eucalyptus leaves and nothing else. Because beavers' teeth never stop growing, they must constantly gnaw on objects to keep them at a manageable length. Their teeth would eventually grow into their brain if they didn't maintain them. Beware an ant uprising! There are one million ants for every human in the world. These resilient creatures also never sleep and do not have lungs. Oysters can change gender depending on which is best for mating. Butterflies have two compound eyes consisting of thousands of lenses, yet they can only see the colors red, green and yellow. A snail can grow back a new eye if it loses one. You can tell a turtle's gender by the noise it makes. Males grunt and females hiss. Giraffes have no vocal cords and their tongues are blue-black in color. Millions of trees are accidentally planted by squirrels that bury nuts and then forget where they hid them. Humpback whales create the loudest sound of any living creature. Dogs' nose prints are as unique as human fingerprints and can be used to identify them. The slowest fish is the seahorse, which moves along at about 0.01 mph. Pigs communicate constantly with one another; more than 20 vocalizations have been identified that pigs use in different situations, from wooing mates to saying, "I'm hungry!" Contrary to popular belief, French poodles actually originated in Germany. Hummingbirds are the only birds that can fly backwards and their wings can beat at up to 80 times per second.