Does the human body contain gold? Can eating spinach really make you stronger? Quench your curiosity with the fascinating facts behind every-day mysteries.Why do you laugh when tickled?Why do cactuses have spines?How do peanuts grow?How do Chameleons change colour?People are allergic to cat hair. False!Why are some clouds white, while others are grey or black?How do cicadas sing?How do fireflies light up?How do spiders make webs?High heels were invented for men!Why does helium make your voice high?Why does the tower of Pisa lean?