Our cats put up with a lot. They chase after red lights that disappear, they're not allowed to scratch up the sofa like they want to, and sometimes they even have to share a house with dogs!
All of this can really sour their mood. Cats aren't exactly big rays of sunshine most of the time, but when they've had a bad day they can be really grumpy.
The difference between humans and cats is that when cats are upset they always let you know. See if you recognize any of these angry stares from some cats that just aren't in the mood.