Harry Potter star Katie Leung loved getting up to mischief on the set of the fantasy movie - because the crew never reprimanded the young stars.
The Scottish actress, 19, would be constantly caught laughing and giggling with the rest of the young cast while performing a tense scene, but the typically humourless film crew would allow it because of their tender age.
She says, "In the new film (Harry Potter And The Order Of The Phoenix) there are scenes in the Room Of Requirement which involved a lot of the pupils - and Rupert (Grint) would just start giggling for no apparent reason.
"Once he started everyone else would find it hard to not laugh too and once we started it was incredibly hard to stop again.
"The crew would get really wound up because they were trying to get the scene over and done with. But we got away with it because we are kids."