I rushed to my friend's house. With fresh new sawdust on the table, I reasoned there must be fresh new worms nearby. I crawled under the table and found a 1/4-inch white worm inching its way across the floor--a furniture beetle larva. My friend's kids thought this was a great game and found their mother 10 more wiggly worms.
There are four kinds of beetles that leave sawdust mounds. All are very destructive. They eat furniture, floors, books, and papier-mache. Their favorite is wicker, including wicker baskets. Look for powdery sawdust on the floor, inside drawers, or (as in our friend's case) sticking to table legs. The cure is difficult. Use a bug spray made to be used for wood-boring insects. Follow instructions, but first check in an inconspicuous spot because sprays may discolor wood. Repeat the treatment monthly for two years. As a last resort, call an exterminator.