I actually find teenagers more annoying to sit near than smaller children - ten-year-olds can be intimidated into good behaviour...

One of the most annoying flights I've been on was a transatlantic trip where the ~16 year old girl behind me kept kicking the back of my seat despite repeated requests not to.

Still - being of the 'spare the rod and spoil the child' school, there are definitely some children who belong in the cargo hold. Parents who don't keep their kids under control make me see red, as do families where both parents are travelling with several small children and the husband ignores everything they do, leaving his wife trying to deal with it all - not fair when you have a hungry crying baby and a couple of toddlers running riot in the aisles.

UMs can be told off without fear of reprisals from their parents!