Quote Originally Posted by Miss Z
Well, all I can say is that Tia is not depressed. If I introduced any other rat to Tia, she would kill it, no doubt about that.

That reminds me! There are some rare cases, where rats simply don't accept cagemates. All rats are completely different. I have a rat who is housed alone because of a handicap. I know what my rats moods are, and he isn't depressed, either. He gets loads of time out of his cage to be with me.
Though, I still suggest to always keep them in pairs^^. Its the cutest thing to see when you walk in and they're all piled ontop of eachother in a hammock.