The horse should keep its mouth closed over a properly-fitted bit (slight chewing is acceptable and a sign of relaxation) and hold its head quietly. A bit may need to be adjusted either higher or lower until the horse shows no signs of discomfort. The height of the bit in the horse's mouth has little significant impact on its severity. Some riders mistakenly think that raising or lowering the bit increases its effect, but this is not correct. The bit is most effective when properly adjusted. Improper adjustment only causes discomfort, not increased control.