American Fancy Rat and Mouse Association 
International rat and mouse club for show and pets.
http://www.afrma.org/London & Southern Counties Mouse and Rat Club 
Founded in 1916. Describes varieties of both animals and includes digital library, book list, and membership information.
http://www.miceandrats.com/index.htm
Rat and Mouse Club of America - Southern California Chapter 
Club information and links to resources, as well as Furry Friends Orphanage in Southern California.
http://www.rmca-socal.org/
Australian Mouse and Rat Information Service 
AMRIS international mouse and rat welfare and pet care information service and newsletter. Rodent adoption shelter to re-house unwanted domestic rats and mice.
http://www.geocities.com/petsburgh/reserve/5824/
Bay Area Rat and Mouse Club of America 
Local chapter in California. Includes a list of local shelters.
http://www.rmca.org/barmca/
RMCA 
Rat and Mouse Club of America. Includes club information, events, contests, merchandise, rat standards, vet recommendations, and magazine subscription information.
http://www.rmca.org/
Eadie's House 
Group of individuals dedicated to the prevention of small mammal cruelty and abuse. Information on their activism, photographs of rats for adoption, contact information for rescuing retired lab rats, and links to other rat rescues.
http://www.eadieshouse.org/