http://www.catinfo.org/?link=litterbox

All you ever wanted to know about litter boxes and cat preferrences.

I for one ended up having to sequester one of my cats to a separate room. Turns out that she simply just did not get along with the other cats. She's been by herself for over 10 months and has had 100% litter box use!!

I also give a rave for Dr. Elsey's Cat Attract litter!!