Nancy's Earth Day project turns into chimpanzee chaos in the nineteenth book in the interactive Nancy Drew Clue Book mystery series. Nancy, Bess, and George need to create an Earth Day project for school, and they've landed on the perfect idea: Chimpiñatas! These globe-shaped piñatas are enrichment toys made for the chimpanzees at the Hairy Hideaway animal sanctuary to enjoy. The girls have filled them with the chimps' favorite healthy snacks, like seeds and fruit, but when the chimps crack open the piñatas, they find that one of them is filled with candy! Who could have switched out the Chimpiñata, and why would they want to make the chimps go bananas? If anyone can find the schemer behind this sugar rush, it's the Clue Crew!