No need to hire a cat whisperer to understand your furry-friends moods, just get this Purrfect Mood Detector.  The detector will let you know when your cat wants to be social.  The microphone will pick up when your kitty is purring, then a LED light that is attached to a collar will light up.  If the lights shining then you know your cats happy, if it's not,  just avoid your feline-friend till their mood changes.  Cats and people have some of the same behavior like,  give attitude - get attention. To bad they don't have these for people, then you could avoid those people with big attitudes!