I use Tru-Air filter. It's that small wall mounted unit that costs about $30 CDN. You can get it at Wal-Mart or any other store like that. Works great!!! I have 35 animals and fair amount of feeder insects in my bedroom along with a kitty litter box (that I can't seem to keep up with changing - I blame this partly on the air filter doing such a good job I don't notice it needing to be cleaned
) and you can't smell a thing! Havent tried it on my feeder/breeder rodents (yet) since they are in the basement, but I do have a few rodents included in the bedroom count as well....