The natural world is filled with diverse--not to mention quirky and odd--animal behaviors. Consider the male praying mantis that continues to mate after being beheaded; the spiders, insects, and birds that offer gifts of food in return for sex; the male hip-pocket frog that carries his own tadpoles; the baby spiders that dine on their mother; the beetle that craves excrement; or the starfish that sheds an arm or two to escape a predator's grasp. Headless...