Well, why not? Is it because elephants are too large or heavy (after all, they say hippos and rhinos can play hopscotch)? Or is it because their knees face the wrong way? Or do they just wait until no one's looking? Read this brilliant new compilation to find out. This is popular science at its most absorbing and enjoyable. That is why the previous titles in the New Scientist series have been international bestsellers and sold over two million copies between them. Like Does Anything Eat Wasps? (2005), Why Don't Penguins' Feet Freeze? (2006) and Do Polar Bears Get Lonely? (2008), this is another wonderful collection of wise, witty and often surprising answers to a staggering range of science questions, from 'why is frozen milk yellow?' to 'what's the storage capacity of the human brain in gigabytes?'.