Carpenter Bee Damage: What it looks like and what you can do about it
They might seem harmless. Hell, we even think they’re a little cute. But carpenter bees are no joke. These little pests use their strong jaws to bore perfectly round holes in wood, and fixing carpenter bee damage can be downright expensive. But, before you can do anything, you need to know how to identify this damage and what you can do about it.
And this guide has you covered.
What are carpenter bees?
Carpenter bees are wood destroying insects that dig their nests in soft wood species. It’s important to recognize that these bees simply dig into the wood. They don’t eat it as they can’t digest cellulose like termites or silverfish.
They’re large, black and yellow insects that measure about 1 inch long, and they have shiny black abdomens. They’re much fatter than honey bees, wasps, and hornets, and larger (and less hairy) than bumble bees.
Usually, these bees will pick a tree to call home, but they’re just as likely to choose your deck, front steps, eaves, fascia, or wooden gutters to set up shop, as well.
They can cause a lot of damage over time. The same family of carpenter bees can excavate their homes year after year, riddling a piece of wood with holes and tunnels.
Carpenter Bee Behavior
First, it’s important to know a little bit about carpenter bee activity. As opposed to honey bees and bumble bees (the latter of which carpenter bees are often mistaken for), carpenter bees are not social. This is to say that they don’t live in large colonies with hundreds or thousands of other bees.
Instead, carpenter bees are solitary, but they form units. Units typically consist of one male and one female, though their offspring may choose to hang around, as well. There are some cases where carpenter bees can live in small social nests, but nothing to the degree that bumble bees or honey bees would.
Unlike termites, and similar to carpenter ants, these bees do not eat wood. Instead, they chew wood with their strong jaws and remove it from the nest. Instead of wood, these bees eat typical bee foods, including nectar and pollen.
They’re Pollinators
As these bees bounce from flower to flower in search of pollen and nectar, they’re also pollinating. Their obviously lower numbers than honey bees or bumble bees make them less prolific pollinators, but they pollinate nonetheless and their removal should be considered carefully (but there are times when they have to go!).
Males Vs Females
Males and females look and act differently. First, you can tell male carpenter bees from female carpenter bees because the males have white marks on their heads while females do not. Female carpenter bees are also the diggers, while males watch out.
Also, male carpenter bees do not have stingers and they do not bite. Female carpenter bees sting, as they do have stingers, but they’re unlikely to use them unless they feel threatened or trapped. And while males don’t have any built-in weaponry, they make up for it in sheer bravery: they dive-bomb humans and animals that get near their nest repeatedly until the threat leaves.
How to tell them apart from other bees
It’s important to be able to tell these bees apart from others. Pollinators are in ever-decreasing numbers, and knowing which pollinator you’re dealing with will allow you to make a wiser choice on removal or even prevention.
| Bee Type | Size | Colors and Description | Nesting Behavior |
| Carpenter Bee | Around 1-inch long and very round | Yellow and black with shiny black abdomen | Solitary, lives in a unit made up of one male and one female |
| Honey bees | Around ½-inch to ⅝-inch long and slender | Brown and black with fuzzy bodies | Social, lives in colonies of many thousands of bees |
| Bumble bees | Around ¾-inch long and round | Yellow, black, and brown with fuzzy abdomens | Social, lives in colonies of hundreds in the ground |
| Wasps and hornets | Length varies, but most are long and slender | Colors vary but may include yellow, black, brown, white, red, and more, but bodies are typically hairless | Varies |
Carpenter Bee Life Cycle
When adult carpenter bees meet and mate, the mated pair head off to find a home. Once they find a suitable spot, the female digs the hole while the male stands guard to ward off any threats.
The female will dig the entrance hole until it’s around 1 inch deep. Then, she’ll turn right or left and continue digging tunnels, heading in the direction of the wood grain. She’ll dig 5 or 6 tunnels in this manner that she can use to lay eggs. Most of this occurs during the early spring, but timing can vary based on location.
Eggs hatch in late spring and early summer, after which it takes 5 to 6 weeks for the pupae to become adults. They’ll then spend the rest of the year eating pollen and nectar, and they’ll overwinter in their holes. In the spring, they’ll find a mate and either reuse existing holes or dig new ones.
Once they mate, the males begin to die. Females typically live long enough to lay eggs, but they will too die before their second winter. However, several generations of the same bee family can reuse the same galleries year after year, though each female will drill her own gallery tunnels. While this is far from a carpenter bee infestation, it can still pose a problem.
What does the damage look like?
On the surface, damage from a carpenter bee is actually quite inconspicuous. Usually, it appears as nothing more than a ½-inch diameter hole in the bottom of a board. It’s not until they see a big, fat carpenter bee flying in and out of this hole that most homeowners realize that they’re looking at damage from a carpenter bee.
If the homeowner were to remove the board from its place and slice it open lengthwise, the damage inside the nest would look quite different. They would be able to see several tunnels (5 or 6, typically), extending down the board, heading in the same direction as the woodgrain. The females use these tunnels to lay their eggs, seal them inside with a ball of pollen, and allow their pupae to grow and mature.
Is carpenter bee damage dangerous?
Small damage is rarely dangerous. The wood is typically still structurally sound, so homeowners don’t have much to worry about as far as structural damage is concerned.
The issue comes when several generations reuse the same entry hole. While they’re inside the wood, each subsequent generation will dig its own tunnels, which can lead to networks of tunnels measuring several feet long and diminishing the structural integrity of the board.
Why carpenter bees damage wood
These bees damage wood out of instinct. They need nests to raise their young, and they’ll use any wood they find suitable. Truly, they’re bugs of opportunity.
They’re building galleries
The main reason that female bees damage wood is to build their nests or galleries. These tunnels allow them to lay eggs safely within a structure, seal their eggs off with balls of pollen and chewed wood, and then live out the rest of their days bouncing from flower to flower.
It’s not that they hate your pergola or rue your siding color. They’re simply responding to nature.
Multiple generations can use the same entrances
In many cases, these aren’t starter homes for these bugs. Carpenter bee nests can often house two or three generations of bees, making them more of a family home. In this way, multiple bees will use the same entry hole, but the females will each dig their own galleries for their egg-laying.
Signs of Carpenter Bee Damage
Carpenter bees can bore their holes quickly, but the extent of their damage is typically limited. However, it’s worth knowing what this damage looks like to help avoid it getting worse.
Sawdust
Homeowners who find piles of coarse sawdust underneath their wood structure might want to look up. There may be a female hard at work digging her gallery and dropping sawdust out of the entry hole to keep things clean.
Bee Poop
Carpenter bees often defecate right outside of their entry holes. This feces is usually pollen-colored yellow or orange. If homeowners see a hole with yellow or orange discoloration under or around it, it’s probably the work of a female carpenter bee.
Dive-bombing male bees
If you’re out mowing the lawn or watering the grass, you might get a good dive-bombing at the hands of a male carpenter bee. More often than not, this is an indication that a carpenter bee’s gallery is nearby, and the male is attempting to run you off.
Entry Holes
The obvious sign of a carpenter bee nest is an entry hole. Usually, these holes are on the underside of a board or log, but they may also be on the sides. Carpenter bees love all bare wood, including raw wood, pressure-treated and untreated wood, sealed, and (sometimes) painted wood from many species. They even chew exposed wood from bug-resistant species like Douglas fir, redwood, and cedar. If there are ½-inch sized holes in a board, it’s likely from these bees.
Woodpecker Activity
Increased woodpecker activity in a tree, on a fence, and other outdoor wooden structures can be signs of these bees. These birds know that there are bees inside the wood and are trying to peck them out. In many cases, this makes the holes look more elongated, but you won’t have to look out for these birds or regularly inspect for them—you’ll definitely hear them.
How To Control Carpenter Bees
Learning how to prevent carpenter bees can be very difficult. It’s not as simple as cutting the grass to get rid of clover mites or draining puddles to control midges. The same family of bees can live in a gallery for years. Also, since they don’t care what type of wood they dig into, they can be literally anywhere. Here are some tips:
Prevent Them
The best way to deter carpenter bees is to prevent them. Pressure-treated and stained wood isn’t effective at keeping these bees away, but paint can be. Use high-quality exterior paint to protect the wood and prevent other bees from finding it so attractive.
Another form of prevention that homeowners can use during the busy season is a preventative spray of water and almond or citrus oils. These oils are repellents for bees and may be effective at keeping them off of expensive outdoor furniture and wooden decks (though they’re not a guarantee).
Dusts and Sprays
One of the most effective ways to get rid of carpenter bees is to use insecticide dusts or sprays. These products contain chemicals that will kill the carpenter bees quickly. However, it can be difficult to apply these products to the entry holes as they need to be administered inside the hole to ensure that the carpenter bees come in contact with them.
Traps
Homeowners can also set carpenter bee traps up around their property to control the population. These traps are essentially wooden boxes with holes drilled in them, and they have glass bottles attached. As the carpenter bee enters the hole, it will travel along the tunnels inside the box and eventually fall into the glass jar, where it cannot escape. It eventually dies in the glass jar and the homeowner simply empties it.
Provide Housing
One other way that you might consider keeping these bees from attacking your deck or siding is to actually provide them with housing. Despite what you might think when they bore into your woodwork, these are beneficial insects and they play a very important role. If you provide with them a carpenter bee house (essentially a predrilled gallery), they may decide not to make a home in your Adirondack chairs.
How To Fix Carpenter Bee Damage
If fixing the damage is the focus, there are a few methods you can try. Our favorite involves wood glue and dowels.
1. Kill the bees inside the hole using whatever method you choose.
2. Purchase exterior-grade wood glue and a dowel that just slightly exceeds the size of the holes.
3. Use a drill bit to drill the entry hole to the exact diameter of the dowel.
4. Apply a bit of wood glue to the end of the dowel.
5. Insert the dowel into the hole and tap it with a hammer until it’s in.
6. Use a hand saw to cut the excess down from the wood.
This method will fill the void and prevent future carpenter bees from reusing the same entry holes.
FAQs
That’s a lot of information about carpenter bees and the damage they cause. However, there may still be some gnawing questions that need answering. The following are some of the most frequently asked questions about the topic.
Do carpenter bees do structural damage?
One carpenter bee’s nest is generally fairly small and doesn’t cause a lot of structural damage. However, these bees often share their entryways to their nests with their offspring, and these bees then chew their own galleries inside the nest. If this goes on for generation after generation, it can result in structural damage.
Can carpenter bees destroy your house?
Over time and with many, many generations, carpenter bees can cause significant structural damage. However, this is highly unlikely.
Should I worry about carpenter bees?
In some ways, it’s wise to worry about carpenter bees. They can drill holes in expensive furniture or torment you every time you walk by their nest. However, it’s important to remember that these are pollinators, so it’s best to be responsible.
Should you get rid of carpenter bees?
Carpenter bees are pollinators and play an important role in an ecosystem. However, they can cause damage to wood work and structures. For that reason, many people decide to get rid of them.
Are carpenter bees hard to get rid of?
Unlike bumble bees or honey bees, carpenter bees don’t live in large colonies. Because these are solitary bees, a carpenter bee infestation is highly unlikely. This makes killing the bees themselves very easy. However, since they can bore through wood all over the home, it can feel like getting rid of them takes forever.
How long do carpenter bees stay around?
Carpenter bees only live about a year on average. However, many times future generations of the same bee family will reuse the same entry holes, making it feel like the same bee is returning year after year.
