1. Meowing when you're asleep.
2. Knocking things off surfaces, especially when you're asleep.
3. Destroying your furniture.
4. Standing directly in front of the TV during crucial plot points.
5. Sleeping on your laptop when you're trying to work.
6. Sitting on the one thing you need right now.
7. Trying to eat your feet.
8. Completely ignoring your presence.
9. Getting in any suitcase as soon as you open it.
10. Showing you their belly and there being a 50% chance it's just a trick and they're going to eat your hand.
11. Yowling when their bowl isn't completely full.
12. "Accidentally" getting a human when they're busy scratching the furniture.
13. Bringing live vermin into your house.
14. Begging at the door for ages and then deciding that they don't want to go outside after all.
15. Spreading their litter around the house as much as possible.
16. Licking their butt in the middle of room, usually when you have visitors.
You're glad they do it – you just wish they had a little modesty.