How to Get Rid of Carpenter Bees – DIY Solutions

There are 500 species of carpenter bees.

These bees, unlike termites, do not consume wood. They just use woods to nest.

Carpenter bees love lumber from ash, California redwood, cedar, cypress, Douglas fir, mimosa, mulberry, pecan trees southern yellow pine, and white pine.

They hate hardwoods the most.

Their favorite place to live in is wood without paint or bark that is still in good condition.

These bees impair structures by drilling holes into timbers to construct nests and lay their eggs. They set up nests inside wood, making galleries of chambers that can eventually weaken structural wood.

If left untreated, this can lead to weakened structure and damaged property. This is why it is important to prevent carpenter bees from boring into the wood structures before they can even start. In any case that they already have, proper management is the key.

Before discussing how to get rid of carpenter bees, it is vital to first learn about their characteristics and life cycle as these will play essential roles in managing them.

Carpenter Bee or a Bumblebee? 

It is easy to confuse carpenter bees with bumblebees because of their close resemblance in appearance.

However, it is important to know that you are dealing with the correct bee before you try to eradicate them.

We have an article dedicated to the difference between carpenter bees and bumblebees. But in summary….

Bumblebees are big social bees, with black and yellow body markings and hairy abdomen. They build nests underground and spend most of their time obtaining food by flying from their nest to the flowers.

So, What do Carpenter Bees Look Like?

These bees are non-social and large like bumblebees. The females are ½ to 1 inch long with metallic blue sometimes purplish or shiny black reflections. Their abdomens are also black, shiny and with no hair.

While they are also good pollinators, they have nests in trees or structural wood. The male bee gets the most attention because he likes hovering around his territory and will go after other insect flying near the nest’s vicinity.

Although the male carpenter bees approach people, they don’t sting. The female carpenter bee, however, can sting but only does so when handled or molested.

Where Do Carpenter Bees Live?

Now you know what carpenter bees look like and you are almost certain that what’s flying around in your home is a carpenter bee, you’re probably keen on finding out where do carpenter bees live.

We already established that these critters love wood, especially the 2-inch thick ones, and use it as their home, but how do you pin point where exactly the carpenter bees nest is?

Check out this video to see what the signs might look like: ​

Only one generation of carpenter bees are produced per year.

Majority of their activities take place in the spring of April or May when young adult male and female carpenter bees emerge from their tunnels to mate. This is after a long winter of staying in their nests.

After mating, the lady bee bores into a suitable wood as the male bee shoos intruders. Once the main ½ inch perfectly round entry is done, the bee will turn and make 6 to 10 inch deep tunnels.

These tunnels are then divided into 6 to 8 cells or chambers where eggs are laid and the holes are plugged with regurgitated nectar and pollen. This mixture seals the larvae in and as it goes through its pupal stage it serves as nourishment until late summer when they become adult bees.

Come late fall, these grown adult bees tidy up their former nest cavities in preparation for winter. Then their life cycle begins again.

The Best Way to Keep the Carpenter Bees Away

It doesn’t matter if you are looking at one or multiple carpenter bee holes because the hole is just a confirmation that there was or still is a nest in there.

The number of bee holes is not representative at all of the extent of the galleries inside. There are cases when tunnels extend to as much as 10 feet into the timber.

This is due to some carpenter bees using old tunnels as nests and enlarging it. Sometimes different colonies use a single entry hole that connects different networks of tunnels.

This is why it is important to know how to keep carpenter bees away.

Preventive Approach

The primary approach to keeping carpenter bees off your property is prevention. Carpenter bees love softwoods, so your properties must be made from hardwoods to keep them from attacking it, especially the exterior structures such as panels and walls.

Apply varnish or paint regularly on exposed surfaces to avoid weathering and keep bees away. Fill cracks, gaps or depressions in wood surfaces to ward off bees that are looking for nests.

​Natural Prevention

There are ways to remove carpenter bees without killing them. Here’s the various strategies in summary.

Plug the Hole

For some reason, trapped carpenter bees do not excavate their way out of a wooden structure. This makes plugging the entry holes easier and more cost-efficient.

All that needs to be done is fill the hole with simple caulk, steel wool or a generous layer of putty. Once the putty is dry and flat, apply paint on the surface. This should keep the bees trapped inside and shoo away other bees that wish to try.

Suck Them Out

This is highly effective when the nest is new because the colony only has 20 or so bees and a queen.

Make sure to do this early in the evening upon the bees’ return to the nest and are still slow. Ready the vacuum cleaner’s suction at the entry hole then agitate the wood structure where the nest is. Make sure to suck out all the bees.

If you are confident that the nest is small, you can poke the nest with a stick and have the vacuum cleaner ready by the entrance to suck the bees out. Be careful of the queen though because she stings.

Once the bees are out, do not forget to fill the hole with putty and cover with paint. If the damage is extensive, you can consider replacing the timber.

Paint it or Layer it

If you have money to cover the costs, it would be a great idea to install vinyl siding or other non-wood siding. If you want to keep the wood siding, just make sure to paint or varnish it regularly to veer bees away.

​Chemical Defense

Carpenter Bee Spray

Among the chemical approaches to deterring carpenter bees is the use of commercially available insecticide sprays labeled for bee or wasp control.

Just apply the insecticide thoroughly and reach as far into the nest as you could. Keep the entry hole open after treatment to allow the remaining bees to touch and spread the chemical into the deeper and unexposed parts of the nest chambers and tunnels.

After a couple of days, you can plug the bee hole with wood putty or carpenter’s glue. This will decrease the chances of future use of old tunnels and keep the wood from decay for longer. Bee or wasp sprays can be used during the day instead of dust sprays.

Other Liquid Sprays

Some liquid chemicals like chlorpyrifos (Dursban), carbaryl (Sevin), or a synthetic pyrethroid (cyfluthrin or permethrin) can be used as a preventive wood treatment applied on at risk surfaces that attract bees.

Because the effectiveness of these chemicals often last for only 1 to 2 weeks, there is a need to repeat the wood treatment ever so often.

Another viable option present in almost all homes is WD-40. It conveniently comes with a long, thin tube you have to insert into the nozzle. Just push the thin tube all the way into the hole as far as it can reach and spray as you pull the tube out.

Just like with other methods, once done fill the hole with caulk or putty and varnish or paint the entire surface of the affected wood.

Dust Insecticides

Desiccant dusts that contain disodium octaborate tetrahydrate or borate (Tim-bor), pyrethrin (Drione Dust), and pyrethroids like cyfluthrin (Tempo Dust) and deltamethrin (Carpenter Ant Dust and Bonide Termite) work best against carpenter bees when puffed into the nests with a bulb applicator.

These are probably the most effective and the most potent but are best left to professionals because inhalation can cause severe lung irritation. Some pesticides, if not all, are poisonous. It is important that directions and precautions are read thoroughly and followed carefully.

But if you want to try your hand in using dust insecticides, take note of these steps:

Locate the timber where the bees built their nest in, this will have an obvious hole and powdery wood dust under it.

At night, while the bees are less active, locate the opening again with the use of a flashlight covered in red cellophane. Carpenter bees cannot see red light which you can take advantage of.

Using a bulb applicator, administer the dust into the bee nest hole. The bulb applicator will facilitate puffing the dust particles deep into the tunnel and coat all sides.

Once done, leave the opening unobstructed so the bees can go in and out freely and unknowingly contact the dust insecticide and spread it into other parts of the nest.

Whenever you are doing your own pest control, it is important to wear complete protective attire. Proper clothing, goggles, gloves and dust mask are necessary to prevent chemical reactions.

Once done, wash all paraphernalia used and make sure not to combine it with other items in the laundry. Bathe immediately to wash off any insecticide particle on your skin or hair. Also, be responsible and handle pesticides with care.

Keep it out of children’s and animals’ reach and store it in the original and properly labeled containers. If it is all consumed, dispose of used empty containers immediately following proper waste disposal of poisonous matter.

It is due to these risks that it is advisable to allow licensed pest control professionals handle carpenter bees in your home. They have the proper equipment that go with their exterminating skills.

Right Time To Treat For Carpenter Bees

The best time to treat is when the carpenter bees are first observed before their nesting activity starts, which is usually around early spring.

Come mid-summer, another treatment must be done to wipe out any bees that might not have gotten adequate treatment when they flew out of the nest.

In early fall, another treatment must be done to get to any bees in the tunnels and its chambers. You can also opt for doing one treatment during fall when the adult bees are getting ready to hibernate so they are all exposed to the chemical.

While it might help, it usually does little help to bombard active nests with insecticides in late spring to summer because this is the period when lady bees are carrying in a lot of pollen and it seals off the chambers with the eggs safe inside.

The insecticide might not be able to get into the larvae anyway and the growing carpenter bees can excavate their way out when the insecticide is way past its viability. Whichever treatment schedule you choose, remember that only after a day or two from the last chemical treatment, are the holes to be completely sealed off with steel wool, wooden dowels with carpenter’s glue or wood putty.

The final step is to varnish or paint the whole wood surface to protect it from future carpenter bee attack.

Carpenter bees in general are thought of as beneficial insects.

This is because they aid in pollinating open-faced flowers and a wide variety of noncrop and crop plants. In most conditions the damage caused by these bees can be dealt with and successfully controlled through the preventive approaches described above with no need for employing the chemical approach.

But if and only if the damage caused by the carpenter bees is extensive that it can cripple a structure or cause any serious problem, in that case call an exterminator and replace the timber. 

Sources:

https://entomology.ca.uky.edu/ef611

https://extension.psu.edu/carpenter-bees

https://www.orkin.com/stinging-pests/bees/carpenter-bee