★A rhinoceros' horn is made of keratin, the same stuff as hair.★Ketchup was once sold as medicine in the 1830s.★The Eiffel Tower can grow up to 6 inches taller during summer.★We have mapped more of Mars than of our own ocean floor.★So far, two diseases have successfully been eradicated: smallpox and rinderpest.★Your stomach gets a new lining every 3 to 4 days, otherwise it would digest itself.★Rats laugh when tickled.★A cloud can weigh more than a million pounds.★More than half of all people alive today have never made a phone call.★The average person spends six months of their life waiting for red lights to turn green.★A snail can have up to 25,000 teeth on its tongue.★Cleopatra lived closer in time to the Moon landing than to the building of the Great Pyramid.★A snail can sleep for three years straight.★Starfish can regenerate their lost limbs.★Sea otters hold hands while sleeping so they don't drift apart.★A mosquito has 47 teeth.★The human brain uses about 20% of the body's total energy.★A day on Venus is longer than a year on Venus.★The Great Wall of China is not visible from space with the naked eye.★Pigeons can recognize themselves in a mirror.
★A rhinoceros' horn is made of keratin, the same stuff as hair.★Ketchup was once sold as medicine in the 1830s.★The Eiffel Tower can grow up to 6 inches taller during summer.★We have mapped more of Mars than of our own ocean floor.★So far, two diseases have successfully been eradicated: smallpox and rinderpest.★Your stomach gets a new lining every 3 to 4 days, otherwise it would digest itself.★Rats laugh when tickled.★A cloud can weigh more than a million pounds.★More than half of all people alive today have never made a phone call.★The average person spends six months of their life waiting for red lights to turn green.★A snail can have up to 25,000 teeth on its tongue.★Cleopatra lived closer in time to the Moon landing than to the building of the Great Pyramid.★A snail can sleep for three years straight.★Starfish can regenerate their lost limbs.★Sea otters hold hands while sleeping so they don't drift apart.★A mosquito has 47 teeth.★The human brain uses about 20% of the body's total energy.★A day on Venus is longer than a year on Venus.★The Great Wall of China is not visible from space with the naked eye.★Pigeons can recognize themselves in a mirror.