We Are All Completely Beside Ourselves  by  Karen Joy Fowler, who wrote The Jane Austen Book Club, about a family who tries raising a chimp as one of their own children.  (Mostly this isn't a good idea).
It's a bit of a surprise or trick story, since she starts telling the story in the middle - actually it's quite similar to Sara Gruen's  Ape House. Kind of a trend lately for some reason. Anyway it's a very good read.