Illustrator Lili Chin produced this wonderful explanation of her dog's body language.
Dog Body Language translation
A Handy Guide to Cat Body Language. #Truth
You can tell a lot about how a cat is feeling from its tail and ears. This site has excellent information, including how to communicate with your cat.
"Cat Tail Speak" from Fun Cat Facts #81...*I remember that my sweet Buffy did the "Crazy about you" tail a lot and I thought it was funny...now I miss it. CLICK to see all 100 Fun Cat Facts...VERY INTERESTING!