What can I do to keep my rats living longer

The "Over Two Club for the Dearly Departed" will give you a clear picture of this

http://spazrats.tripod.com/o2cdd.html...

Depending on whether or not they have good genetics to begin with some rats are very old at 1.5 years, while some are still spring chickens at 2.5 years. I have had over 200 rats so far and I've been through the gambit of aging and diseases with my rats.

If you want rats to live longer then 2 years old, if you want rats that live to a ripe old age of 3 or more without succuming to hind-end paralysis at an early age (plagues the old male rat), or mammary tumors at an early age (plagues the old female), then you must avoid pet store rats at all costs. Pet store rats are quantity-bred rats with little thought put to their health and longevity. They are like feeder comets (goldfish). They were never meant to live for a long time, so they weren't bred to.

Instead, look for quality-bred rats from reputable breeders, and here's a place to start,

The Ratster http://www.ratster.com/

Ok, so you have rats now and you want them to live longer. There is so much to talk about for a rat's health and care that I couldn't possibly say it all in this one answer. Pet rat-only Yahoo groups, where you can continuely talk to other rat-care experts on this subject, would greatly benefit you and your rats. Don't go it alone, get advice. I know it sure has helped me help my rats live longer, in the last 11 years.