Do Carpenter Bees Come Back To The Same Nest Every Year?

Whether you're trying to get rid of carpenter bees from your home, or admiring their talents at helping flowers reproduce, you may have some questions about these bugs and how they may or may not affect your home. These inch-long flying insects that go by the scientific name Xylocopa virginica are distinctive-looking bees whose common name evokes industriousness. If you're watching one of these hairy-yet-shiny bugs fly in and out of a piece of trim on your home, you might wonder if carpenter bees come back to the same nest every year. The answer is not so straightforward, but it might incite some curiosity about this petite animal's life cycle. Although not all individuals return to the same nest year after year, some do come back — and if they don't, others may move in instead. To further complicate the subject, some may even overwinter in the nest.

People often find carpenter bee holes on their decks or on the trim underneath rooflines. Carpenter bees drill holes into wood and then keep expanding tunnels while they make nests for their offspring. This species either makes nests that are solitary or composed of small groups of family members. The females who build these tunnels can live from one to three years, and those who live long enough will keep coming back to the same nest. Even though the same mature individual may not come back to the same tunnels every year, the tunnel she helped to excavate will be reused by her offspring or unrelated carpenter bees. 

While foraging for food for their offspring, these bumblebee look-alikes (or all black, if they're female) help pollinate the plants in your garden, so while some might consider them pests, others see them as beneficial insects. And they don't always build their tunnels into the wood materials on your home — they also build their nurseries in standing dead trees and logs. However, if the type of natural habitat they need isn't available, you might find some holes in your home's woodwork, and may notice bees coming back to the same nest every year. If this is your case, you'll be happy to know that the holes they make usually only cause cosmetic damage. Considering the carpenter bee's role as pollinator, you might feel encouraged to take a gentle approach instead of trying to simply eradicate them.

Prevention is the best strategy for wood that is unaffected. Painting or staining the wood is one way to make it unattractive to these bees. And you can also keep carpenter bees away with clever nesting alternatives, like building nesting blocks for them out of softwood such as pine. One way to prevent them from returning to old nesting sites is to wait until they vacate and fill the empty holes with steel wool and caulk. The use of insecticides is only recommended in the case of severe damage, and if used, should be applied with caution since doing so can come with health risks.