Shooting can take the form of 'walked up' (where shooters walk across the moor to flush grouse and take a shot) or 'driven' (where grouse are driven, often in large numbers, by 'beaters' towards the guns who are hiding behind a line of 'butts'). Many moors are managed to increase the density of grouse. Areas of heather are subjected to controlled burning; this allows fresh young shoots to regenerate, which are favoured by the grouse. Extensive predator control, including illegal killing of raptors, is a feature of grouse moor management: foxes, stoats and crows are usually heavily controlled on grouse moors. The extent to which it occurs on grouse moors is hotly contested between conservation groups and shooting interests, and the subject generates a lot of media attention in relation to grouse moors and shooting.