Years ago we live trapped a baby male pack rat and instead of killing it, give it to a lady friend's son. Within a few weeks the rat was completely tamed and friendly. Used a cat litter box.
The local vet just laughed and neutered it and gave it all its shots. Packman grew up to be HUGE....as big as a small cat. He was well behaved, affectionate and learned many tricks.
The only problem was when lady friends were visiting my lady friend, they would freak out when Packman jumped in their laps wanting to be petted. HB of CJ (old coot)