Question: You recently wrote about floor joists in older homes. It had to do with powder beetles and treatment with borax. What exactly do these beetles do to the wood? - B.B., Reading, Pa.

Answer: Powder post beetles, if found, are in the adult stage and do not damage lumber or furniture. It is the larvae that grow inside the wood that do all the damage. If you have wood or furniture with small round holes that look like drill holes, you may have beetle larvae in the wood.

Also look for a fine sawdust powder, or frass, below the hole where the adult bores its way out. Prying open damaged lumber you may find the larvae.

You can also clean the frass from below the holes and inspect regularly. If more frass is found, you have active beetle infestation.

The beetle larvae consume the wood and can cause serious structural damage if left untreated. Treatment is often simple in areas that are easy to get to.