Living with a cat can be great fun, very active and filled with affection. But it is important to remember that cats operate on instinct rather than intellect the way humans do. This means they don't so much reason things out and assess them as react on what their instincts tell them to. This means that cats can get angry for reasons that may not seem worth it to us and this can lead to an injury if dealt with in the wrong way. Here we look at the signs that your cat is angry.