This activity shows students how a blue whale's baleen "teeth" work and introduces a complex conversation about nutrient density: why is it that the largest creatures on the planet (whales, elephants, etc) eat the smallest foods? How do these tiny foods support life? This is a companion activity for If My Mom Were A Platypus: Mammal Babies and their Mothers. The title is available at a discounted price for Title 1 schools on the First Book Marketplace. This book explores how 14 different mammal babies navigate the path from helpless infants to self-sufficient adults, and comes with a free downloadable Teacher’s Guide filled with activities just like this one.