I wonder why snakes shed their skin：and other questions about reptiles I wonder why snakes shed their skin and other questions about reptiles I wonder why snakes shed their skin :: and other questions about reptiles / Originally published: as I wonder why snakes shed their skin and other questions about reptiles 1996 I wonder why lemons taste sour：and other questions about senses I wonder why stars twinkle：and other questions about space I wonder why stars twinkle and other questions about space I wonder why ponies wear shoes：and other questions about horses I wonder why stalactites hang down and other questions about caves I wonder why whales sing：and other questions about sea life