Doctor Dolittle's Zoo by Hugh Lofting audiobook.
Doctor Dolittle, the man who can speak with the animals, is back home but running short of money to care for all the animals who need his help. He invites animals into his garden and encourages them to build their own societies and come and go as they please. This works very well. He has a mouse and rat town, a dog community, a burrow for badgers, and so forth. This does not make any money and only gets him into trouble with his neighbors. But the stories told by these mice and rats are entertaining and fun. And there is a mystery too, which Kling, the dog detective, helps solve. All of this with Lofting's usual delightful whimsy and light hearted touch that make you smile at every other sentence.