There is probably another thread out there about this that I haven't found, but I thought I'd post one anyways. :D
I have found over the years that by having a pet, in my case my golden retriever, has helped me with my anxiety. Jake, who is now 9, has helped me through a ton of rough patches...
Ok, so the rats were just relevant to my interests. And that picture is so darn cute. But this is a whole feature on animals and how they express joy.