How To Get Rid Of Carpenter Bees With WD-40

The detrimental effects of carpenter bees might surpass the valuable roles they play. Over time, several elimination measures have emerged to curtail these effects. But, carpenter bees are beneficial, so killing them may not be the best thing to do.

how to get rid of carpenter bees wd40

WD-40 is a common, thin oil spray that is famous for its many uses. It is present in many homes because it serves many household functions. WD-40 is effective in stain removal, lubricating metal parts, and thawing frosted surfaces. It is also believed to have repellant and insecticidal effects on pests.

Hence, it is also used to get rid of carpenter bees. In this article, we will explore the effectiveness of WD-40 on carpenter bees, and how it gets rid of them. We also have a bigger guide on how to naturally get rid of carpenter bees.

What is WD-40?

WD-40 is a brand name for a water-displacing spray product. It is an oily substance that has very low viscosity and acts as a lubricant and penetrant.  WD-40 is petroleum-based and contains mineral oil, carbon dioxide, and aliphatic hydrocarbons. Though it lubricates rusty metal parts, it leaves little residue when applied. Due to this volatility, WD-40  should not replace an actual lubricant.

WD-40 also acts as a cleaner and adhesive remover. It prevents rust, frost, and corrosion from metal tools.  As a result of this versatility, it is popular in various homes.

Does WD40 Kill Carpenter Bees?

WD40 will kill carpenter bees and just about any other insect if they come into contact with enough WD40 and for a long enough time period. WD40 contains a collection of mineral spirits which is toxic to insects and can kill most insects within around 5 minutes. So if you’re wondering will wd-40 kill carpenter bees, the answer is yes!

How To Get Rid Of Carpenter Bees With WD40!

Applying WD-40 directly to bored carpenter bee holes or directly to carpenter bees has proven to be moderately effective in eliminating carpenter bees. To be safe, don’t ever apply the spray near an open flame, and don’t ingest or spray the liquid into your eyes.

using WD-40 for carpenter bees

• As a Makeshift Pesticide

WD-40 is an oil-based product that is capable of killing carpenter bees and other insect pests.  The mineral oil and hydrocarbons contained in WD-40 are toxic to insects. When it comes in contact with the bee, it interferes with its respiratory system. This works by obstructing the free flow of oxygen and shutting off the air holes (spiracles) of the bee. This results in the blocking of the trachea and the death of the bee by asphyxiation.

The mineral oil contained in WD-40 can also kill carpenter bee eggs laid inside the holes on the wood. WD-40 can form a thin oil layer on the exterior of the egg. Hence, ceasing the exchange of gasses between the egg and its surrounding. WD-40 can act as a poison by interfering with the bee’s metabolism and causing a breakdown of its systems.

• As a Pest Repellent

WD-40 can also repel carpenter bees and other insect pests from attacking surfaces. Though, as light oil, it is volatile and leaves very little residue. Hence, it may not be very effective as a repellent for an extended period. Still, it can be effective as an insecticide.

Carpenter bees are sensitive to smell, using this sense to locate nectar-producing flowers. Strong-smelling substances like varnish, paint, or WD-40 can disrupt their olfactory senses. Applying these substances on wood surfaces can repel carpenter bee attacks.

How to Apply WD-40 on Infested Areas

1. Find and identify infested regions in wood

Nest holes made by carpenter bees are almost round in shape and about a half-inch in diameter. Softwood such as cedar, pine, oak, and redwood is the best nesting choice for carpenter bees. Also, they attack wooden structures such as doorposts, railings, roof eaves, and decks. You may also find carpenter bees infesting unpainted or untreated wood. Observe carpenter bees hovering around your structures and inspect any hole you find.

2. Insert the WD-40 extension tube into the carpenter bee hole

The aerosol can of the WD-40 comes with a straw-like extension used to apply the spray in tiny areas. Stick the extension into the hole, as deep as it can go, and spray the WD-40. Spray for at least 10-20 seconds to coat the inner holes with WD-40. Foamy WD-40 will seep out through the hole, as the pressure created from the tiny hole will push excess of it out. Make sure to clean up any spilled WD-40 liquid on the ground or any other non-wood surface.

The evenings are best to do this treatment because the adult bee is most likely to be resting in the nest hole.

3. Shut Nest Holes

Spraying the nest holes with WD-40 and plugging it immediately will limit airflow in the nest. then, speed up the killing of the bees. Use wood putty or caulking clay to cover the hole after spraying. Read our guide on repairing carpenter bee damage!

Using WD-40 to Prevent Carpenter Bee Attack

1. Identify Pre-existing Holes

Look out for holes and crevices in your wood structures susceptible to attack. Make sure to cover with small wood dowels, caulking, or wood putty.

2. Apply WD-40 on unstained or untreated wooden surfaces

WD-40 can repel carpenter bees from infesting wood. You can also use it to prevent other insect pests from invading your wooden surfaces. Paint or stain your wooden surfaces to make them unfavorable for carpenter bees.

Safety Procedures:

WD-40 is a petroleum-based product that may be corrosive and may cause allergies. So you should take great care when handling the product. Put on safety goggles and hand gloves to prevent droplets from getting into your eyes or on your hands. You can also put on a face mask to avoid inhaling it. Make sure not to spray close to open flame,  WD-40 is flammable and may cause fires.

Adverse Effects of WD-40 on the Environment

Petroleum-based products—including WD-40—are unsafe for the environment because they are non-biodegradable. WD-40 contains carbon dioxide which is a greenhouse gas that depletes the ozone layer. It is toxic to carpenter bees and other insects and can kill them on contact.

Instead of killing carpenter bees, you can fend them off with repellents. You can also use live traps to capture them. You can also set bait wood, for the bees to exploit, rather than your wood structures.

Final Thoughts On Carpenter Bees and WD-40

One of the effective ways to get rid of carpenter bees is using WD-40. As a popular petroleum-based lubricant, WD-40 is toxic to carpenter bees. It has constituents that can repel or cause them to die off. Spray it in infested holes and cover them to kill the bees and prevent further attack. Also, make sure to carry out safety precautions before use.


About The Author:

David Floyd has 20 years of experience working as a pest control technician as well as running his own pest control company. His main goal is to provide accurate and helpful DIY tips to keep your home pest-free and how to identify different types of household pests!