Children annoy me as well.
I used to hate it when a girl would invite me to babysit with her and then I'd have to put up with some little honeysuckle or multiple little shits for 3 or 4 hours. I hate the little ones who think everything is ammunition, as soon as you think they're out of objects to throw at you some crayola flys into your face. They also do that thing where they stare at you and pull faces. Then they'll run into a door and start crying. Then when they're finally in bed and I start getting cuddly with her He'll walk through the door and say that he can't sleep and he'll tug on her hand until she's forced to go sit with him for half an hour -_-
Then there's the situation where a mother asks you to look after her kid for 5 minutes whilst she goes back into the supermarket to buy something quickly. You can guarantee she'll take 30 minutes and you can guarantee that the kid will keep running in front of cars or picking up dog crap.
Then there's kids in general who can eat half a sandwich and then have enough energy to run a marathon. Running around everywhere screaming. The only thing worse is when one of them crys. That's the most awkward situation in the world and the noise drives me insane.
Although, I would like to be a father some day. If it was my own child I could put up with anything. I would be praying for a girl though. A Pezza junior would not be cool.