A carpenter bee burrowing into a wooden deck

The Buzz on Carpenter Bees

carpenter bee7

When most people hear the words stinging insects they think of honeybees, yellow jackets or wasps, and the threat of being stung by one of these sometimes ornery pests. There is, however, a stinging insect whose appearance and sound is much more frightening but is actually more of a threat to the wood railings, posts and wood siding on the exterior of your home than it is to you.

1 Carpenter_bee

Carpenter bees are often confused with bumble bees and when seen up close appear to be HUGE, but actually they are usually only 5/8 to 1 inch in length.  They are shiny black with metallic blue reflections and while their appearance is intimidating only the female carpenter bee can sting and will only do so if provoked.


carpenterbee3Carpenter bees do not live in hives, but build their individual nests in wood.  This nest building can weaken the structural integrity of wood, as well as leave unsightly holes and stains on a structure’s surfaces. Their entry holes could earn the praise of a skilled finish carpenter since they are perfectly round, with a drill like appearance.

Female carpenter bees bore into healthy wood to establish their nests but they will also attack dead wood on trees or lumber from southern yellow pine, white pine, California redwood, cedar, Douglas fir, cypress, mimosa, mulberry, ash, and pecan trees. In most instances they avoid hardwoods.



A carpenter bee’s nest usually consists of ½ inch diameter tunnels that extend 6 to 10 inches into the wood and includes multiple chambers. These skilled excavators will expand their tunnels and have been known to burrow as far as 10 feet into wood timbers! With those skills I sometimes wonder if they have an engineering degree!

They mate and lay eggs in the spring and new adults emerge in late summer to feed on nectar and pollen, and then overwinter, often in old tunnels that they have stocked with pollen.

carpenter bee According to the Agriculture and Natural Resources service at the University of California, carpenter bees are generally considered beneficial insects because they help pollinate various crop and non-crop plants. But how do you keep these noisy insects from boring into the wood around your home?

You can follow my Five Tips for Controlling Carpenter Bees to make the wood around your home less attractive to infestation:

CARPENTER BEE_clpd1.) When possible use hardwoods for exterior construction of posts, siding, etc.; Carpenter bees will not normally bore into hardwoods.

2.) Fill depressions and cracks in wood surfaces with caulk or suitable material to make them less attractive to carpenter bees.

3.) Paint or varnish exposed surfaces regularly to reduce weathering and make it less prone to attack.

4.) Fill in unoccupied entry holes with steel wool and caulk to prevent their reuse. Do this after the bees have emerged in late summer and while they are getting ready to hibernate for the winter. Once filled, paint or varnish the repaired surfaces.

5.) Protect exposed rough wood areas, such as ends of timbers, with wire screening or metal flashing.

If the carpenter bee infestation is significant or is posing a serious threat to the structural integrity of the wood I recommend that you call a pest management professional – stinging insects of any kind are nothing to mess with.


One of my Western Exterminator highly-trained service technicians can inspect your home and provide you with a report of findings. If treatment is required, we will also provide you with recommendations and design a customized program to treat the tunnels and seal up the holes to prevent future infestations.




Do you have questions about carpenter bees, or any other structural pest? If so, I want to hear from you. You can send me an e-mail at [email protected]. I’ll be sure to get back to you right away with more information.


Until next time, thanks for making Western Exterminator Company “The Final Word in Pest Control®.”

Have a pest free day.


Mr. Little

He’s represented Western for nearly a century. But he’s no old fogey. Follow Mr. Little’s blog for pest tips and facts!

Leave a Reply



Call your local branch


or fill out your details and we will call you back

Bill pay and login