My kid has this habit of biting his nails. How can I correct this habit of his?

My 5yr old son don't do this but my husband does! :) Nail biting is one of the most common childhood habits. I believe understanding this behavior by talking to your kid, asking questions like - is he/she is aware or conscious when his biting his nails? what does he/she feels if he/she does that? if he like or don't like it? why? in general, understand why his doing that habit and let him understand the consequences (in the future) if he continues doing that.