Stanley and the Class Pet by Barney Saltzberg

From chapters.ca:
Finally! It is Stanley’s turn to take the class pet home for the weekend. He can’t wait to show Figgy to his mother and spend some quality time taking care of the bird. But when Figgy flies the coop, Stanley is faced with a very tricky problem. What to do? And whose fault is it, really — his, for agreeing to open Figgy’s cage, which he knew was a bad idea, or Larry Finchfeather’s for suggesting it? In this third story about the lovably earnest Stanley Birdbaum, everyone’s favourite hamster once again finds a way to make things right — with a little help from his friends.