Cool guinea pig facts!

Just wanted to share a cool fact i learned about guinea pigs. Did you know that there used to be giant guinea pigs roaming the earth? They were 9 feet tall and could swim in the water (semi-aquatic mammals). They were called the Phoberomys Pattersoni aka "guinea-zilla."
My source: http://www.guineapighub.com/guinea-pig-facts.html

I also want to try to start a thread here for cool guinea pig facts! Anything else you've learned about these awesome little critters?

 

Another cool fact: through scientific research, guinea pigs helped us discover Vitamin C. Both humans and guinea pigs aren't able to produce vitamin C naturally, so research on the cavy made it possible for us to create an external source of vitamin C!