Cats typically don’t smile for the same reasons that humans do. Usually people smile when they’re happy or feeling sociable. In comparison, cats often smile when they know they’ve gotten away with something big, like creating the financial collapse of the world economy and then getting a government bailout to fix the problems they created.
While cats may not smile for the same reasons that humans do, their smiles often give you a chance to check their teeth. Rather than rely on a smile to determine your cat’s mood, watch your cat’s eyes. A slow blink means that the cat is happy and wants to be friends.