Being a Pig is Nice: A Child's-Eye View of Manners by Sally Lloyd-Jones, illustrated by Dan Krall

From chapters.ca:
A book about manners, all from the point- of- view of a little girl. In her refreshingly subversive world, monkeys must always use their fingers when they eat or get in trouble, elephants are encouraged to squirt and splatter everywhere, and pig parents ask their children to get muddy before they go to bed. Of course, if you're a pig, you smell, and that's not nice. Still, the girl can see that behaving like an animal could be fun....