I am currently pet sitting two rats. I absolutely love rats. These two sweethearts are dumbo rats. Both are super affectionate, love to cuddle (especially Dumbo) and lots of fun.
Both rats have full access to my downstairs bathroom, they are not caged and they are loving it.
For anyone looking to board a "small critter" it can be cage free. It is a small but spacious well ventilated area where your little critter will be safe and comfortable.