Large Carpenter Bees

Carpenter bees belong to the bee family ‘Apidae’.   

Large carpenter bees belong to the genus Xylocopa, and small carpenter bees to the genus Ceratina

This page is about large carpenter bees.

Xylocopa - Large Carpenter Bees

More than 500 species of Xylocopa are known to exist world-wide, and most are found in tropical and sub-tropical regions. 

However, they are also found in the USA and Canada, and some are found in Europe.

Violet Carpenter Bee - <i>Xylocopa violacea</i> - a large dark bee with iridescent blue and purple sheen to its body and wings.Above: Violet Carpenter Bee - Xylocopa violacea.

The Xylocopa violacea, pictured above, is generally found in southern Europe, although it has recently been discovered in the UK.  I have read that this species lays the largest egg of any insect!  

These species can sometimes be mistaken for bumble bees.

Nesting Habits

Not surprisingly, these bees get their name because they are known to make their nests by boring holes in wood.

Eastern carpenter bee - a stocky bee about the size of a bumble bee, with a blackish abdomen and pale ginger thorax.  It's foraging on pink flower blossom.Eastern Carpenter Bee - Xylocopa virginica

In fact, Xylocopa is the Greek word for "wood worker".  These clever bees then then use small amounts of wood chips to form partitions between the cells in which they lay their eggs.

Small amounts of sawdust may be visible around nest sites, although old nest tunnels may be used.

Although they are solitary, with some species, females may live alongside their own sisters or daughters, thus forming a basic social group.

Do Carpenter Bees Sting?

Like other species, they will sting only if provoked, and are mostly interested in foraging and going about their business. Read about  bee stings and treatments.

It's interesting that most people feel threatened by males, despite the fact that males cannot sting (see my page on which bees sting and which don't).  However, they are territorial, and it can come as a bit of a surprise if they seemingly fly at you!  They seem to be attracted to you the more you waft your arms around.

The females are able to sting, but like bumble bees they are docile, and will rarely do so.

Carpenter Bee Lifecycle

Carpenter bees emerge from hibernation in the spring, around April or May. They overwinter as adults in wood within abandoned nest tunnels.

By late spring or early summer, you may see them hovering around as they search for mates and suitable nesting sites. After mating, the fertilized females excavate tunnels in wood.

As with some other solitary bees, the female constructs the nest alone. She lays her eggs within a series of small cells, each supplied with a ball of pollen on which the larvae feed. The larvae emerge as adults in late summer, and hibernate until the following year.

Pollination And Carpenter Bees

Carpenter bees are great pollinators, and are generalists, meaning that they will visit a large number of flowering plants (depending on what flora is available) to gather pollen and nectar.

They are similar in size and shape to bumble bees - and indeed, some species are frequently mistaken for Bombus.

Their large, furry bodies are superb for pollination, as pollen is trapped on their hairy bodies, and is easily transferred from flower to flower.

The crops pollinated by carpenter bees include passion fruit, Brazil nuts and cotton.  Like bumble bees, carpenter bees are also used in greenhouses to pollinate tomatoes - this is practiced in Australia.

Do I Need To Get Rid Of Them?

Some people are keen to get rid of these bees if they discover they have them, however, these types of bees do not always cause significant damage, although some species may cause damage. However, please read the personal accounts below of people who have written in to BuzzAboutBees!

Carpenter bees are more inclined to make their nests in rotting old or damaged wood. This can lead people to believe it is the bees themselves that have caused the damage, but very often it will be a sign that the wood needs to be replaced in any case.

However, they may also target soft wood.  If concerned, it is better to check carefully and take steps if necessary (see my advice to a reader below).

Bees are excellent pollinators of flowers and plants. It is better to engage in preventative carpenter bee control, rather than using pesticides or trying to kill carpenter bees.  Always maintain woodwork, keep it well painted and in good condition. These bees are not out to make work for themselves by selecting hard, painted wood that will be more difficult for them to bore into.

Reader Experiences Of Carpenter Bee Nests

I received an email from a Mr Wayne Robey of Indiana.  He wrote:

Just an observation:

I have a lot of carpenter bees here in Indiana and drilled some holes in their favorite 4 x 8 soft timber but most prefer to make their own entry holes about 3/8" in diameter and on the bottom of the wood, and many have chosen unpainted white pine under the eves of the house, some on nearly horizontal parts but more on wood at a 45 degree angle.

After painting these areas in the spring the old holes were still in use but there are no new ones.

Wayne Robery

The lesson seems to be that keeping vulnerable areas painted could be a good deterrent to carpenter bees.

I was also touched by an email in which a gentleman described how he had lived with carpenter bees for 15 years, and enjoyed having them around.  Unfortunately, there came a time when this gentleman needed to get rid of the carpenter bees, because he had to rehab and sell his home.  He describes a situation in which he used insect repellent to deter the bees (I tend to recommend deet-free repellents rather than poisons to kill the bees.  They are available from or

Anyway, his account of observing the bees over the years is an interesting one, and fortunately I was given permission to share it on this website:

Carpenter Bee Nest & Pictures
By Myran Michaelis

I once lived in a mostly brick ranch house (Ohio Huber) and had a stack of 1x2" pine boards on my back patio for some reason.

Shortly, I noticed sawdust at the base of the stack and one bee-hole about halfway up.  Since my house was mostly made of bricks, I was not alarmed. Over a period of >15 years, I observed the bees. Usually when I would come out there would be an out-rider, or 'lookout bee' that would observe and interact with me.

Some years in, I decided to get rid of the board stack (at least 60 boards high). I figured most of them would be riddled with bee-holes but was surprised to find that the bees had only nested in a single board, gouging out a small bit of the board below to gain access.

I removed all but the main board (+10' long) and cut a 4-foot section of the under board containing the gouge to save as a foundation.

Not long after, I came home to find a bee drilled thorax-deep into my wooden garage door. I stroked its little bee-butt with my finger, causing it to withdraw and fly hastily away. I then sprayed insect repellent on the bee-hole. No bees ever bothered my garage door after that.

Some years later I sadly needed to rehab my house to sell it, and since I was moving to an all-wood house, I could not take my bees with me. We rehabbed in winter, so the bees were too dormant to flee from my table saw.

I ripped the 10' and 4' boards lengthwise and killed all the bees. The 4' board had 1 access hole and 1 nest. The 10+ board had ~15 access holes and ~13 nests, 4 with nesting compartments and 2 of those plugged. A couple of the access holes were in-and-out, meaning that the bee drilled in and then abandoned the hole due to proximal tunnels in the board. There are many instances of bees tunneling through the edge of the board and turning back.

Also, I would dispute your claim that these bees prefer dead/rotted wood. I have only observed them chewing up firm and healthy wood. I do not mean to criticize here, but merely observe.

Also, I do miss my bees.

Myran's Photographs - published with permission:

The location of these nests was a suburb of Dayton in SW Ohio. I have two boards with tunnels in them, the upper board being about 10 ft. long and the lower being about 4 ft. long. Although the lower board does have a nest in it, these pictures were all taken from the upper board.

carpenter bee hole and tunnel in wood plank

This was the original hole I noticed in the 5 foot stack of 1x2 boards on my back patio. Notice that the hole starts into the side of the lower board, then immediately turns up into the upper board. For about the first 8 to 10 years, this was the only hole.

carpenter bee tunnels in wood plank

This shows the extent of the original nest between approximately 1990 and 2009.

carpenter bee hole and tunnels in wood plank

This shows another nest in the upper board.

close up image of carpenter bee hole and tunnels in wood plank showing 'compartments'

This shows a ‘nursery tunnel’, compartmentalized for the individual bee babies and having the access hole plugged with what appears to be mud. Several of the other tunnels in this board appeared to have been compartmentalized in the past and then had the partitions removed. The partitions also look as though they were made out of mud.

carpenter bee holes in wood plank

This shows the underside of one end of the board. Ten access holes are visible, with one being plugged up (not the same hole as shown in the picture above).

multiple carpenter bee hole and tunnels in wood plank

This shows 9 nests accessed by the holes plus one in-and-out hole and one bonus nest whose access hole does not appear in the 05 picture. I use the term in-and-out to describe a case where a bee dug straight into the board and broke through the surface of the other side, then withdrew and abandoned the hole. There are two in this board, both very close to existing tunnels.

close up image of carpenter bee hole and tunnels in wood plank

This shows a close-up of the bonus nest in the picture above.

image showing nursery tunnels in wood plank of the carpenter bee

These show a second ‘nursery tunnel’ and a close-up of it.

nursery tunnels of the carpenter bee in a plank of wood

This shows the lines presumably left after a tunnel had been used as a nursery and then had the compartment barriers removed. These can be seen in the outer two tunnels.

close up image of the nursery tunnels of the carpenter bee, with a little of the compartment barriers remaining but mostly removed.  Entrance holes also present

This shows the lines presumably left after a tunnel had been used as a nursery and then had the compartment barriers removed. These can be seen in the outer two tunnels.

in and out holes in the plank

This shows a close-up of the first in-and-out hole (the two holes right next to each other at the edges of the board halves). Note that it barely penetrates the top surface of the board

in and out holes in the plank of wood - very neat in appearance.

This shows the second in-and-out that was drilled through a very tight space bounded by three other tunnels. Again, the bee chewed clear through to the upper surface of the board. This hole also broke into one of the tunnels, though the break was later patched over as shown in the upper right quadrant of the hole.

My comment:

I'm always interested to learn of people's experiences, particularly when they challenge the established ideas!

I have come across many writings regarding carpenter bee preference for soft & rotten wood. However, it does sometimes seem that the more we observe wildlife, the more inclined we are to change our ideas about it!

I liked the fact that Myran lived with the bees for years, that he felt able to accommodate them for such a long time, until he needed to move house.  It made me smile!

A Request For Advice

I received an email message via my contact form, asking the following question.  I thought I would share it, because certain large carpenter bees are often mistaken for bumble bees, and I felt the advice and insight might be interesting for other visitors.  Thank you to Lisa for allowing me to publish her query:

From Lisa, USA:

"I am fascinated by what my husband calls a worker bumble bee.

Every spring when the bees come out to play, a bumble bee hangs out by my deck.

I swear he comes when I call. He guards the deck from any other insect including other bumble bees. He chases them away.

I will often go to the door and say "hello bee" and he will come to the door and hover as if listening to me. I know that all this is coincidence, but I like to think he can hear me.

As soon as anyone goes on the deck, it's like he is hanging out with us, keeping guard.

I love having him, but what is he actually doing?  Right now I have not put any plants out and he is already here for a couple of days. Thank you".

My response to the query above was as follows:

"Dear Lisa

From the behaviour you describe, it sounds like you have carpenter bees rather than bumble bees.  Some carpenter bees do indeed look like bumble bees, in that they are quite ‘roundish’ in appearance. 

Male bees are very protective of the nest, chasing off insects, and investigating human ‘trespassers’!  

Indeed, in a sense, when you call ‘hello bee’ from your door, he is indeed ‘hearing you’ – by that, I mean that he is probably picking up the vibrations and investigating the intrusion accordingly, to see if there is a threat to the nest.

(You can read more about this on my page 'Do bees have ears/how do bees pick up sound?').

So in fact, there is no coincidence here, and you are not imagining things, and yes he is seemingly ‘hanging out’ with you and ‘keeping guard’ to ensure you don’t harm the nest. 

However, all this is bravado on his part.  Male carpenter bees (just like other male bees) cannot sting.  They are completely harmless.

Another alternative is that you have a male carpenter bee prospecting for a mate.   Anyone/anything is chased off, until a potential sweetheart arrives on the scene! 

Bumble bees do not (as far as I am aware) exhibit this kind of behaviour in defending nests.  Worker females (all workers are female) do defend the nest, but from inside it.  For this reason, dead bees may sometimes be found outside a bumble bee nest entrance, following a conflict within the nest (followed by some tidying up and clearing out!).

For your information, some carpenter bee species can, over time, cause some damage to woodwork.  If the woodwork is crucial, I suggest you keep it painted and well maintained to deter them, because they prefer soft and old, untreated wood.  Try to locate the nest if you believe you have one, and examine it to see if it is causing damage (it is the females that do the burrowing and nest building). 

If there is damage, but the wood is not important, then it is nothing to worry about – or you may wish to relocate the piece of wood if you can, a little further from the house at the end of the year, if you are concerned.

I hope this helps."

If you have a similar situation, I recommend the following steps to locate the nest and/or protect structures, such as the timber structures of a home:

  1. Are there any vulnerable areas that could be soft or rotten or unpainted?  I would check these first. 
  2. Second, check the eaves of the house.
  3. If there is no sign, simply go through checking any vital structures you would be concerned about.  If you know these are safe, you will have some peace of mind.  It could be something not to worry about - such as the leg of an old garden chair, or old wooden box that you can move away.
  4. Look out for other bees of the same species and watch where they land.
  5. I do recommend you also treat your wood, especially if you live in an area with carpenter bees. You might come across the nest in this way.  Prioritize any soft/untreated/old wood, and important structures.  If you come across a worrying problem, then if you can, remove the piece of wood and replace it entirely - this is the best if you can do it.  Take the wood away from your home. 

    If this is not possible, you may have to block the holes with caulk if you fear serious damage to vulnerable structures.

    If there is nothing to worry about, you can leave the carpenter bees alone.  They may not be causing a problem and they are excellent pollinators. 

You could also try a repellant, a natural one that is free of DEET - or one that contains Picardin, to deter future nests.  

Do bees sleep?
Apparently they do, but how do we know?

Sleeping honey bees, links to the page 'Do bees sleep?'

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