Many dogs chew and dig out of boredom. For Chewing - Don't leave the little buggers inside alone. If you can't watch 'em, crate 'em. Put them outside, or someplace where they can't eat everything you own when you can't supervise. Most out grow this.
Labs seem to be the worst and it takes up to two years - they have an extended puppyhood.
Of course, give your chewer lots of chew toys. Chewing outside is a bit more of a problem. Try a pepper solution painted on whatever you want to protect. No this isn't cruel. No chew, no pain.