After taking a stink bug into his big sister's room because he thought she might like to play with it, a little brother begins a quest for the answer to a question that has been bugging him for a long time.First he asks his dad.Then he tries to ask his mom.But, eventually, his quest to find the answer takes him back to his big sister's room because she is the one most qualified to answer the question: WHY DO GIRLS SCREAM?