Sea urchins, with their prickly spines, are one sea creature you don't want to step on. Readers discover how sea urchins use their tube feet to breathe, move, and grab food as it floats by. Also discussed is the key role sea urchins play in many ocean food webs. A two-page spread offers even more information, such as the fact that a sea urchin's teeth never stop growing. The colorful design and amazing photos are sure to draw in young readers and keep them engaged while learning fun, science facts.