i hear the voices when I'm dreaming

Many of these animals you are mentioning, such as mice and bunnies, are social and do best with a companion in most cases, unless you adopt one from a shelter that has already had a history of wanting to be all by itself. But really, I think two animals as opposed to one really isn't that bad, especially when you are talking about smaller animals where they really should be in a cage big enough to fit two even if you just have one anyway.

Maybe guinea pigs? They are kinda docile and lap sitty, from what I hear!