Does your child bite their nail?

My five year old bites his nail to the point they bleed. I have tried "polish" that you put on their nails that is very biter and will stay for days. It worked if I kept his fingers painted all the time. I ran out and ordered some more (what I bought in hair supply store was a joke!) but this time he eats his fingernails  like like their  candy. Have you moms out there had/have this problem and what did you do?

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