Nail biting is a very bad habit, which can rapidly become uncontrollable.mavala mava stop is a with product harmless bitter taste, having the appearance of a colorless varnish, which helps break the habit of nail biting or bring his fingers in his mouth. It has a bitter taste and the appearance of clear enamel. Helps break the nail biting habit and finger or thumb sucking. To use without or over your nail polish. For children (over 3 years old) and adults. With small children the efficacy can be compromised as their taste buds are not fully developed and they may like the bitterness of the product.