Does you child bite their nails or suck their thumb? Mine bites his nails to the point that they bleed. I searched the internet for the best ways to get him to stop. I found everything from wearing gloves all the time to talk therapy..to a 4 year old???? Then I kept seeing good reviews for a nail paint called Mavala Stop. I purchased some and boy did it work. It lasted for days and my son did not bite his nails. When I was diligent about keeping them painted I had to cut his nails for the first time since he had enough teeth to bite his nails. I have learned to keep enough because I need to keep his nails painted all the time to break his bad habit. When I ran out of Mavala recently he started to bite his nail again badly and I purchased another brand and it does not work. With in 30 min his fingers are back in his mouth. If you need something for this problem Mavala Stop works.