Carpenter Bees: Appearance, Common Traits & Behavior

I had mistaken carpenter bees for bumblebees all my life, and now I am endlessly fascinated by how blissfully unaware so many people are regarding this.

That’s no judgment on my part (obviously, since I was one of those people). I just want to clear the air. Carpenter bees are just as interesting and wonderful as their more popular counterparts. Here’s what you need, to be in the know.

carpenter bees

What Do Carpenter Bees Look Like?

Let’s start with the basics. To identify a carpenter bee, first, you’d have to make sure that it is, indeed, a bee.

Bees are part of the order of hymenoptera—cousins to wasps, sawflies, and even ants. Insects who fall into this family are recognizable by their membraneous, somewhat transparent pairs of wings. Like all other insects, bees have six legs and segmented bodies, comprised of their head, thorax, and abdomen.

While wasps and ants have more arrow-shaped bodies, bees are a little bit more robust. Bees have fur and antennae, and thicker, stronger legs than their cousins.

If you’ve determined that what you’re looking at is certainly a bee, you can look at the specifics to determine which type of bee it is.

Carpenter Bee vs Bumblebee

Looking at the characteristics of carpenter bees, it’s easy to see why they’re so often mistaken for bumblebees. The two are extremely similar, and it can be difficult to tell them apart if you don’t know what to look for.

The two are similar in shape. Both are chubby and significantly larger than other bees. Their head, eyes, antennae, and wings are almost indistinguishable from each other. They’re also both yellow and black, and that only adds to the confusion.

So how do you tell one from the other? Funny as it may sound, the easiest way is to compare their bottoms. Carpenter bees are black, while bumblebees’ are yellow. Bumblebees have fuzzy bottoms, while carpenters don’t have fur on their abdomen.

Bumblebees vs Carpenter Bees
Bumble Bee (left) and Carpenter Bee (right

The last obvious difference is that carpenter bees have a black dot on their backs, while bumblebees have the typical yellow and black stripes instead.

How Big Are Carpenter Bees?

There’s a misconception flying around that carpenter bees come in two types—large and small. Yes, there is such a thing as a small carpenter bee, but it’s a misnomer. While they are related, “small carpenter bees,” more accurately called ceratina, are a different species entirely.

There is not much to be said on the size of a carpenter bee. With honeybees, their size depends on their rank in their colony. Queens are larger than drones, which in turn are larger than workers. What they’re fed as larvae determines how big they’ll grow too.

Carpenter bee sizes vary, and they can be anywhere between a half and one inch long.

Carpenter bees don’t live in colonies though, and the differences between male and female bees are superficial. Females have black heads, and males have white markings on their faces. Other than that, they’re almost exactly the same—even in size.

Where Do Carpenter Bees Live?

Carpenter bees don’t live in colonies. They’re solitary bees and as that name implies, they go at it alone, not loyal to part of a bigger community of bees. There are smaller nests though, in which a few carpenter females could congregate.

It’s no wonder that they’re called carpenter bees. They’ve been given this title thanks to both their ability to work wood into homes for themselves, and their saw-like behavior as they do so.

Carpenter bees live in tunnels called galleries, that they drill into wood using their mandibles. From the outside, these galleries appear as perfectly round holes that are only slightly larger than the bee itself. They’re designed to fit the bee’s body perfectly. On the inside, their galleries can be as vast as ten feet long.

wood bee (carpenter) in nest

Galleries are not so different from beehives. Carpenter bees treat them as any other bee would treat a hive or nest. They use galleries to lay eggs, store food, and hide away from external conditions. Carpenter bees even drill cells into their tunnels, much like a honey bee builds cells out of wax.

Carpenter bees store their eggs furthest from the entrance of the tunnels and cells. They seal them off with wood pulp.

Since drilling galleries is time-consuming and requires much effort, it’s not beneath a carpenter bee to take advantage of a pre-existing tunnel. Unlike bumblebees, their nests are not temporary. Carpenter bees can live for a few years, and in that time they may have no need to abandon or replace a perfectly good home.

Carpenter bees prefer soft, untreated wood, but will drill into any other type if it’s all that they can find. Their favorites include oak, redwood, pine, and fir. On occasion, they will settle for painted wood, but typically only if it’s old and worn.

Carpenter Bee Social Behavior

I’ve already mentioned that carpenter bees are solitary, but what exactly does that mean? How do they survive without the support of the colony? How exactly do they take care of themselves?

Social bees are dependent on colonies because not every bee is equipped to complete tasks like foraging or reproduction. In honeybee colonies, for example, drones cannot forage, and workers cannot reproduce.

Carpenter bees, however, can hold their own. They can forage, build, reproduce and defend themselves (except for males, who don’t have stingers). They do everything for and by themselves, so their behavior is different from that of a social bee. It’s not to say that carpenters never group though.

Carpenter bees spend their winters in their tunnels, living off of pollen that they packed into their nest cells. With spring, the adults will leave their tunnels to mate. Willingness to mate is communicated by dancing in groups before a mate is selected.

After mating, the males die and the females move on to find, build, or renovate suitable galleries in which they can lay their eggs. It only takes a few days for the eggs to hatch, and within seven weeks the hatchlings grow into full-fledged adults.

When they reach adulthood, they spend the summer foraging, before they retreat into their own tunnels for the winter so the cycle can continue.

Carpenter bees do not have queens, nor do they have workers. Although male carpenters cannot sting and therefore cannot defend their gallery from threats, they are not quite as purposeless as honeybee drones. Their main purpose is still to mate, but they are known to share almost all duties with females.

What Do Carpenter Bees Eat?

It’s another misconception that carpenter bees eat wood. There are a few differences between the diets of carpenter bees and honeybees though. To start with, carpenters don’t have queens and so they do not feed their larvae royal jelly. Another difference is that carpenter bees don’t make honey.

Other than that, their diet is the same. Carpenter bees feed on pollen and nectar. They’re herbivores, so they get all of their nutrition from these two things. They contain, and so give the bees, carbohydrates, protein, lipids, and multiple vitamins and nutrients.

In fact, it’s been hypothesized that pollen could contain up to 60 percent protein—twice as much as we originally thought.

Carpenter bees acquire their pollen through something called buzz pollination. This is a trait that is often found in solitary bees. Carpenter bees will hold onto a flower, and flap their wings rapidly. The vibrations loosen pollen and make it easier for the bee to collect.

They use their proboscis to collect nectar, the same way that honey bees do, though it’s a little more complicated for carpenter bees. They draw nectar by tearing open the side of a flower’s center. Unlike honeybees, they do not assist with pollination when feeding on nectar.

Females will collect nectar and pollen to feed their offspring back at the gallery. Since they are solitary bees, this is their only responsibility when food is involved. Both males and females are capable of foraging.

There’s no evidence to suggest that carpenter bees will eat human food, most likely because they don’t have a colony to feed or report back to. This gives them more freedom to be discerning in what they take in. Still, studies have shown that if bees are desperate enough, they’ll turn to unnatural sources for food. The last part of a carpenter bee’s diet is water, just as with any other creature.

Are Carpenter Bees Dangerous?

Carpenter bee males come across as aggressive and territorial but it’s only for show. They don’t have stingers, you see, so they aren’t a threat. Females, on the other hand, can and will sting, but they have to be driven to the extreme to do so.

Unlike honeybees, bumblebees, and more sensitive Hymenoptera (like wasps), carpenter bees are not as willing to attack. They have the attitude, though, and won’t sting for no reason. They only use this defense when they feel threatened.

But a carpenter bee female is somewhat more passive than others, and will only sting if she is handled or mistreated. There is still that same willingness to defend her gallery, but more often than not she will only become dangerous if you deliberately interfere with her personally.

There is also less of a threat here because carpenter bees (as solitary bees) don’t swarm. If one stings you, it is extremely unlikely that a horde of bees will follow. This behavior is seen in colony bees that feel the need to protect their nest.

Still, carpenter bees are capable of stinging multiple times. It’s better to rather be safe than sorry. If one stings you, attend to it immediately. Also, people with allergies to bee venom should be extra careful, but that goes without saying.

Although carpenter bees don’t pose that much of a threat in terms of stinging, they are still considered pests by many. This is because their wood-working behavior has the potential to cause damage to our property, so they are not well-liked.

Their reputation deceives them, however, because they don’t actually inflict severe damage to whatever they’ve chosen to drill into. Still, many people prefer not to have them around because there is some potential for structural damage to our homes.

It would take a long time to notice damage caused by carpenter bees, though. The main concern is that their drilling not only damages the appearance of wood (beams in your roof, for example); but the holes can degrade the strength of it too.

This increases the chances of damage from external factors, like water damage or (although it’s unlikely) infestation by other pests.

Drilling also causes wood to discolor, and carpenter bees usually leave behind a yellowish stain where they have bored holes.

As I mentioned earlier, carpenter bees don’t eat wood, they just live in it. They’re often compared to termites but this is entirely incorrect. It may be an annoying problem to deal with over time, but carpenter bees are not capable of destroying your home.

They may renovate their tunnels if their nests need to be cleaned or expanded, causing further damage. For the most part, however, carpenters will settle after their hard work and won’t continue to damage the wood they have chosen to nest in.

Carpenter Bee Conservation Status

Carpenter bees are great pollinators and so are an important part of our ecosystem. Honeybees tend to steal their thunder, but we should thank carpenters just as much for our food.

This means that if carpenter bees are wiped out, we will have just as much of a problem as with honeybees, for the reasons I will point out below. Unfortunately, carpenter bees aren’t as cared for, so they don’t get as much attention.

That said, carpenter bees are not directly under threat. They are not endangered (for now) and there is no evidence that their numbers are on the decline. Still, just because there isn’t a problem now, it doesn’t mean there won’t be one in the future.

Carpenter bees may even be better pollinators than honey bees. Solitary bees don’t have pollen baskets, so they spread more pollen to plants than other bees—dropping more than they can carry.

This, of course, helps plants pollinate faster. If their reproduction is accelerated, more plants are produced and that’s great news for us. The takeaway here is that honeybees are not the only ones we depend on for food.

Although it’s not specific to carpenter bees, they still face the threats that endangered (or soon to be endangered) bees face.

Perhaps the biggest threat to carpenter bees is a shortage of pollen, thanks to our CO2 emissions. Global warming has started to eradicate certain strains of pollen that bees (and other pollinators) depend on. This could lead to starvation, and naturally, the bees and other insects who need pollen to survive will slowly, but surely, die off.

On a simpler level, climate change (as I have mentioned before) also interferes with their feeding habits.

Dramatic changes in climate have confused many different types of vegetation to the point that they grow out of season. Bees have not yet adjusted their rhythms to this, so in the spring and summer, there is a growing shortage of food as well.

What about more direct human interference? Are we actively affecting carpenter bees? We are. In one big, sad way.

Our pesticides are preventing solitary bees from reproducing. This might not be a noticeable problem now, but when combined with the problem of a changing environment, it could have an intense impact on carpenter bee populations.

Over time, their numbers will decrease, and this could likely put them on the endangered list.

There is an even bigger problem though: pest control. The reputation of carpenter bees has led people to believe that if they’re discovered in or around our homes they must be exterminated.

It’s become so much of a problem that I’ve found while researching these sweet, harmless little creatures, there’s more information out there on how to get rid of them than anything else. It’s a sad reality.

As I said, carpenter bees do not pose an immediate threat to us or our homes. If (and this is a big, unlikely if) you have a serious problem with carpenter bees, do not turn to exterminators. Most of them will not relocate the bees—they’ll just kill them. It’s unfair, and cruel, to the carpenters who are just trying to survive—no harm intended.

Summary

Carpenter bees might not be as loved as their bumblebee doppelgangers, or as cared for as the more favored honeybee, but they are still worth some attention. They’re excellent pollinators (hence, vital to our survival) and they rarely pose a threat to humans.

Still, they’re misunderstood bees. There is a serious lack of information regarding their behavior and importance in our world. We should make an effort to get to know them, so we can better conserve them. They don’t need our help now, but if we continue treating them as we do, they’ll likely begin to decline.

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