This makes me silly

"A little girl and her brother go with their family to the zoo, only to find that they can't stop laughing! Between making funny monkey faces and stretching their arms for elephant trunks, it's no wonder they snort out their milk at lunch. The little girl doesn't see any harm in her silliness at first, but when she scares an animal by shouting and banging on the glass, she learns that there's a time and place to be silly (like at the zoo playground), and a time and place to be calm (when animals are sleeping)"--Provided by publisher.