It’s that time of year again; as the seasons change, several common nuisance pests end their life cycles or retreat back to their dwellings to overwinter. One such pest is the carpenter bee.

This large, aggressive insect is known to wreak havoc on decks, trees, wood siding, and other timbers throughout your home.

While beneficial pollinators of the Insecta class, these oversized, shiny black bees are often viewed as pests due to their destructive habits while creating their annual burrows. Unlike common honey bees, bumblebees, and even wasps, which build up their nests/hives, female carpenter bees tunnel into existing wooden structures and decaying trees. After years of repeated burrowing and nesting, these tunnels often lead to serious structural damages and costly repairs. 

Additionally, carpenter bees can be extremely aggressive while protecting their burrows, with male carpenter bees often seen rapidly buzzing past anyone who comes near. Male carpenter bees sometimes fly directly into supposed threats to ward them off.  

Luckily, carpenter bee season is rapidly closing in PA, allowing you to patch up abandoned dwellings and make necessary repairs.

What Time of Year Do Carpenter Bees Go Away? 

Carpenter bees are an extremely common pest with an impressive range, found throughout the entirety of the United States. However, like most insects, carpenter bees are only active during the warmer months of the year. 

Carpenter bees have different seasonal active periods in different regions, with southern carpenter bees experiencing the longest active period from February to October. However, here in PA–where we experience all four seasons–carpenter bees are only active from the end of March to October, hibernating the remaining months. 


essential pollinator that should be protected whenever possible

How Do I Know If I Have a Carpenter Bee Problem? 

The signs of a carpenter bee infestation are relatively easy to spot, especially if you know how to look! Traditionally, female carpenter bees burrow ½” wide round holes approximately 1 to 2 inches into decaying and untreated wood such as felled trees or natural deck boards. The holes then make a rapid turn alongside the natural wood grain, extending an additional 4 to 6 inches. 

Therefore, the first inclination of a carpenter bee nest will likely be the ½” entrance hole, often littered with coarse sawdust and yellow stains from the bees expelling waste before entry. 

Further, while females spend the majority of their time in their burrows, males can often be seen hovering around the entrance, either looking for a prospective mate or protecting their nest. Male carpenter bees are highly aggressive, though they don’t feel the need to run indoors or swat them off. Like many species of bee, males lack stingers or venom glands, instead turning to intimidation tactics such as dive-bombing and crashing into threats. So if you notice a large black bee in your personal space, there’s likely a carpenter bee nest nearby. 

Do They Come Back to The Same Spots Each Year? 

As one could imagine, burrowing a tunnel 4 to 6 inches into solid wood expels loads of energy, which a female carpenter bee also requires to lay eggs. As a result, female carpenter bees often prefer to perform a quick renovation on an abandoned nest from the previous season rather than start from scratch. For this reason, it’s relatively common to see carpenter bees returning to old nesting grounds annually. 

However, this behavior can be increasingly damaging to wooden structures. As carpenter bees return annually, they’ll often burrow fresh tunnels alongside previous dwellings, expanding their nest and reducing the structural integrity of deck boards, posts, railings, and wood siding. 

Tips to Keep Them Away

While carpenter bees may be a nuisance, it’s important to remember that–like all other bees and wasps– they’re essential pollinators to our crops and gardens. As such, treating them with insecticides or exterminating them should be viewed as a last-ditch effort, unless infestations become incredibly severe and annual. Thankfully, there are several methods of keeping carpenter bees at bay without toxic chemicals, including preventative pest control

Cover Up Exposed Wood

Prevention is the best tip for taking care of an infestation before it returns again. Painting or varnishing exposed wooden surfaces is an excellent deterrent, while filling existing burrows will prevent bees from returning.

Use Synthetic or Treated Building Materials in Future Projects

Carpenter bees only burrow in wood; any synthetic building materials such as composite decking or siding are completely resistant to insects, including these burrowing pollinators. Therefore, pressure-treated posts and other wooden building supplies are an excellent option for new structures due to their chemical treatment for pest and rot prevention. 

Localized Pesticides

While insecticides aren’t ever recommended as a first resort, it’s important to use them as little as possible to avoid killing other bees and helpful pollinators. If you must use an insecticide, the preferred treatment methods involve localized chemical dust and spray applications. These treatments are applied onto and around the entry holes into burrows, which reach the carpenter bees as they climb in and out of the nest. Once eradicated, you can then plug the entrances into burrows and repaint.  

When using chemical insecticides, ensure that you’re adorning adequate protective gear and using the product as recommended by the manufacturer.  

While carpenter bees may be a nuisance, they’re still an essential pollinator that should be protected whenever possible. Several prevention methods exist to keep your home free of these pesky pollinators while preserving their population and ecological benefits. 

If all else fails, or you feel overwhelmed by the notion of taking on your carpenter bee infestation yourself, don’t hesitate to contact your qualified local pest control experts below for advice and services. 

Pest Issues? Contact The Pest Rangers Today.