I don't know what it is, but animals make me smile.  We had almost every kind of pet growing up.  A couple of cats (Spike and Froggerber), a dog (Molly), fish (Sausage), and two birds (Harold and Ivan).  If you are a pet owner, you know each pet has their own personality which makes you love them.

One thing I always envied was how some dog owners could train their dogs so well.  While the rest of us spent years trying to train them to do at least one trick, they are somehow able to train their dogs to do something like this...enjoy!