Two months ago, my boyfriend and I adopted a two year old cat named Ritz from the shelter. He got along with the other cats at the shelter pretty well. He adjusted very quickly to our home. We work all day long and felt that Ritz was bored and needed a playmate so we adopted another two year old cat named Dr. House from the shelter and brought him home today. Dr. House got along with the other cats at the shelter even better than Ritz did. Ritz is very rambunctious and playful while Dr. House is very sweet and gentle. When we first introduced them, they sniffed each other and Ritz just followed after Dr. House as he explored. Dr. House hid under the bed for a long time today and Ritz started pouncing at him and licking and biting him, but it seemed very playful. I separated them because I didn't want Dr. House to be stressed out. When Dr. House finally came out, Ritz followed him more and bit him more and Dr. House hissed at him and now Dr. House is hiding under the couch and Ritz is just watching him. Are there any tips anyone can give me on getting Dr. House used to the house and getting the two cats to get along?