I recently had a 10 hour flight from Dubai. Having seen numerous children boarding the aircraft, I knew it was not going to be pleasant. Sure enough I was seated near three children. The youngest child travelling with her parents was a delight; she was very well behaved and was not heard at all.
Unfortunately there was a mother travelling with two children; two badly behaved children. The youngest screamed and yelled for most of the flight. This was not helped by the fact that the eldest bit, hit and punched the youngest regularly.
Using the in-flight entertainment did not provide any relief as the mother could be clearly heard over top of the in-flight music. For the next nine hours the passengers were entertained with cries from the mother as she yelled at her unruly children even though our flight left at midnight. Delightful.