Cats can be pretty suspicious and finicky creatures. Disrupt their norm, and you do not have a happy camper on your hands.
Thinking of switching from wet food to dry? You should probably consult them first. Thought you could just change their litter to the natural, non-clumping kind? Seriously, how dare you?
But when you go and do a thing like bring a new human home from the hospital, that's when you're really giving the family cat cause for concern.
Watch as one kitty attempts to check out this strange visitor in a strange land known as "baby" ... and immediately regrets doing so. ("What are those terrible, awful sounds coming out of it, and will they ever stop?!")