A crocodiles tongue is attached to the roof of its mouth. A rhinoceros horn is made of compacted hair. The cheetah is the only cat that can't retract its claw. Polar bears are the only mammal with hair on the soles of its feet. Anteaters prefer termites to ants.
Some owls have fringes on their primary feathers to enable silent flight.
The largest insects that ever lived on the earth were giant dragonflies with wing spans of over 3 feet. A turtle's shell is nothing more than its ribs and spine fused together over many years of evolution. Cockroaches favourite food is the glue on the back of stamps. Of the 4000 species of mammals on the planet, the are 900 different species of bats.