Hi Lauren,
When I was a graduate student, my advisor named all of our computers after animals that had traveled in space. We put together a web site about them:
http://ham.space.umn.edu/kris/animals.html
Even though NASA does not currently use animals to test whether or not a space vehicle is safe for humans, NASA still does some research on board the Space Shuttle and the International Space Station with animals. This research is done to help us better understand how living things can adapt to microgravity environments. You can read more about this work and the difficulties in making sure animals are properly cared for in space here:
http://www.nasa.gov/audience/forstudents/9-12/features/F_Animals_in_Space_9-12.html
Kris