Clean your wool before storing it. To wash wool without shrinking it, use a shampoo with a pH level below 8 and water around 100 degrees Fahrenheit. Gently swirl the wool in the water with shampoo, rinse it in clean water, then press the water out. Do not wring out the wool.
Let the wool air dry in the sun for a few hours before packing it away.
Make your own natural mothballs. Mix 2 oz. each of dried rosemary and mint, 1 oz. each of dried thyme and ginseng, and 8 oz. of whole cloves in a bowl, then tie the mixture up in one or more bandannas with ribbon or string.
Be sure the wool you're storing is completely sealed, whether it's in a bag, box or chest.
Freeze the wool in a freezer for two days if you see moths.