The only way to fix chew marks is to eliminate the problem before you give them rats with bushy tails a chance to do the damage. I have declared my big sugarbush a war zone. I have shot 73 squirells in the last 4 weeks. I shot about 40 of them sitting on the same stump. Hickory nuts every where. I have won many battles, but there is no cease fire in the near future. The date will be recognized when i win the war.