1. A Rat can survive being flushed down a toilet (depending on the toilet...and the rat of course)!
2. Ganesha, the Hindu god of prosperity, new beginnings and luck rides around on a rat!
3. Rats have glands on the bottom of their feet, so they leave a wet sent trail where ever they walk!
4. The black plague killed more rats then people!
5. Rat packs can go up to sixty strong!
6. Because of their large numbers they can kill larger animals, like lambs pigs and poultry!
7. A rat can swim for three days before it drowns (read 'em and weep Mr. Pied Piper!
8. I've read in National Geographic that a rat could hypothetically survive a fall off of a five story building (all thought I think its safer if we never know for sure!)
9. Rat tails can are used for temperature regulation and communication as well as balance!
10. A group/pack/herd of rats is called a Mischief
Dont try any of this at home kids...such as in number 8 I used the phrase "can survive" not "will enjoy" a fall of a five story building!
-http://www.geocities.com/RainForest/Vines/8377/ratfun.htm
Rats are extremely clean pets and are among the most intelligent and curious.
Ancient Romans considered the rat good luck, and in China the rat is considered a sign of prosperity.
Rats, with their long tail, have a very acute sense of balance; therefore, they are excellent climbers.
Rats can swim and many enjoy it.
Pet rats live an average of two to three years.
Male rats are known as bucks, females are does, and babies are pups or kittens.
Rats are very social animals and do best when kept with other rat companions.
The general rule is that male rats are larger with a coarser coat and more laid-back disposition, than females. Females are typically smaller and more active and playful.
Pet rats, or fancy rats, have an interesting history. Many breeders believe that rats were first widely domesticated by the rat-catchers of the 19th Century. It is believed these people, who were paid by town governments to trap rats, started breeding rats to keep themselves in business, 
only then discovering how intelligent and loyal these pets could be.
Though generally nocturnal, most rats are crepuscular, which means they are most active for a few hours around dusk and dawn, dividing the rest of the day between hours of lesser activity and sleeping.
Rats have starred or appeared in over 400 films and close to one hundred television series.
-http://www.drsfostersmith.com/pic/article.cfm?aid=1272
