I have an allergy to children....but only poorly behaved ones whose parents think it is fine for their little darlings to do exactly as they please regardless of how much they are disturbing others around them. Sadly there are too many of these little brats around and brat parents.

A well behaved child is usually welcome anywhere. However those who run up and down the aisle, kick the seat of the passenger in front of them, play their gaming console at a loud volume, repeatedly bang the tray table up and down and generally shout / scream etc are NOT welcome. Nor are their parents who fail to control them.