NAF Crib Stop is an unpleasant tasting water repellent coating to discourage your horse against stereo-typical behaviour such as crib biting or rug chewing. from biting wood and other hard surfaces. Discourages horses from biting wood and other hard surfaces. Non-toxic and designed for use on surfaces such as stable doors, rugs and rails to discourage chewing. Designed to act as a deterrent against stereotypical behaviour such as crib biting or rug chewing. Unpleasant-tasting, water repellent coating Contains Denatonium Benzoate in a spray bottle.