School-aged Billy must take his preschool-aged sister Belle to class with him while Dad takes Mum to the hospital for the birth of a new baby. It's an exciting and extraordinary day for both of them -- not just because they're getting a new brother or sister but because it's pet day at school. Even with just a last minute notice, Belle manages to muster up a pet of her own to take to school: a spider! The full-color illustrations set in a comic-strip format are filled with amusing details of a bustling home life and a refreshingly disorderly school. Billy and Belle (and baby Adam) are biracial: their mother is white and their dad is Black. (Ages 3-6)