For the past 12 or so years, we've been working with thousands of inbred mice trying to figure out genetically and biologically what makes people either highly active or inactive (i.e. a frantic banana or a couch potato).  Growing up on a farm, I learned how interdependent we (humans) are on animals; so, it is gratifying to know that our mice are helping us to discover basic biological truths and how to be healthier humans.  We are able to answer so many questions for human health that could never be actually tested in humans (I haven't found any humans yet willing to give brain tissue up), so literally, without these little furry creatures, I wouldn't have a job or be able to pursue the questions that are the passions of my life....