How to Get Rid of Carpenter Bees

Carpenter bees are big and stout, and people mix them up with bumblebees all the time. The giveaway is the abdomen. Carpenter bees have a shiny, mostly hairless black one instead of a fuzzy coat. The males buzz around nest sites and act tough, but they can't sting. Only females have a stinger, and they almost never bother to use it.

The hole gives them away. A female bores an entry about half an inch wide, so perfectly round it looks machine-drilled. From there she tunnels several inches in, sometimes branching off into chambers for her eggs. Watch for yellowish staining or sawdust-like debris (called frass) sitting below the openings. Woodpeckers pecking at your siding are another tell. They're after the larvae inside.

One hole looks like nothing. The trouble is what comes next. The same tunnels get reused and extended year after year by new generations, so a single gallery can spread into a wide network running through a beam, a railing, or a fascia board.

All that hollowing weakens the wood and opens the door to other problems. Moisture works its way in. Woodpeckers tear into the siding chasing larvae. And the interior damage you can't see usually dwarfs the surface holes you can, so catching it early really does keep older wooden structures sound.

Carpenter bees go for bare, untreated, unpainted wood, and they're picky about it. Soft weathered softwoods pull them in fast. Older homes take the worst of it because the exposed paneling, trim, and siding have lost whatever seal they once had.

Look around the property and you'll find their favorite spots. Anywhere bare wood catches the sun is fair game for a nest.

Treat the active tunnels directly, then seal them once the bees clear out. That's the method that works. An insecticidal dust puffed into each hole catches the bees as they crawl in and out, where a surface spray usually misses the ones buried deep inside. Do it in the evening, when the bees are home and sluggish.

Give it a few days after treating so the bees pick up the product. Then plug the holes with wood filler or a wooden dowel and caulk over the top. Seal too early and trapped bees just chew a fresh exit. One more thing: don't go swatting at a swarming nest. Carpenter bees turn defensive when you disturb their tunnels, and an exterior riddled with active galleries is the kind of job that calls for proper equipment and protective gear.

Prevention mostly means taking away the bare wood they crave. Painting or sealing exposed wood is one of your strongest deterrents, because carpenter bees steer clear of finished surfaces. When you're building something new, reach for hardwoods or composite materials for the deck and railings.

Some homeowners swear by citrus or citronella scents near problem spots, a candle or a diffuser, plus a few deterrent plants nearby. Those help at the edges. They won't replace a sealed board. Carpenter bees do their nesting from late spring into mid-summer, so finishing your repairs and sealing the wood before spring gives you the best shot at a quiet season.

Lots of holes, a faint chewing sound coming from inside a beam, nests that show up every single year. Any of those means the infestation runs deeper than the surface lets on. And treating high eaves puts you up a ladder right next to defensive bees.

A licensed local exterminator can find every active gallery, treat them safely, and walk you through repairing and sealing the damaged wood so the structure holds up. The hidden damage tends to outrun what you can see, which is the main reason professional treatment is the safest bet for an aging wooden exterior.