Other than the family dog and a bunch of cats, I keep and breed colubrid snakes. I used to have lots of them but I am down to my last 11 breeders. My AP Bio classes raise mice as a part of our genetics projects and they supply the food for the summer breeding season. Nothing goes to waste.
However, since robots take a lot of my time these days, I have changed hobbies in the last few years to one not requiring lots of care. Mineralogy has always been an interest and I spend what spare time is available digging specimens - take a look
http://www.geocities.com/njtraprock/