Roaches seem to eat just about anything. They’re so tenacious when hungry that some people believe a popular rumor that roaches will even eat paint. This may include the unsecured paint cans in your garage or the paint on your walls. Roaches might even eat your decorative paintings.
Roaches do eat certain types of paint. Paints that contain vegetable oils, animal oils, and starch may attract cockroaches. They prefer rotting food, not paints. However, when there is nothing else to eat, roaches will eat paint to survive. Roaches can digest paint without harm, despite the toxicity, because of their highly adaptive genes.
Roaches will most commonly opt for paints that are used decoratively. The coating on your appliances or car won’t appeal to them. That’s because they want the base components in the paint, not the paint itself. Chemical paints will have little appeal. By mixing certain essential oils into your paints, you can repel and even kill off opportunistic cockroaches.
Are Cockroaches Attracted to Paint?
Cockroaches are not directly attracted to paint. They will rarely choose it when human food and waste are available. However, that doesn’t roaches won’t happily eat paint. It depends on how hungry they are and how much access they have to alternatives.
Roaches are omnivorous, which means they eat both animal and plant-based substances. Household cockroaches normally favor decaying foods with fat, starch, and/or sugar. That’s especially true for the American cockroach and the German cockroach.
However, when none of their favorite foods are available, cockroaches will consume the next best thing: other cockroaches. They become cannibalistic when starving. The pests will then happily feast on dead or weaker cockroaches for nutrients.
That leaves paint low on their list of delectable foods. If a smaller cockroach is competing for food with bigger roaches, it will eat paint.
Do Roaches Like Paint?
Cockroaches can eat paint because of what it contains. Many will contain different ingredients, depending on what the paint itself is used for. Because of this, roaches are more commonly attracted to the paint on a painting, rather than the coating on a bicycle.
Most paints are made with chemicals, but animal and food products are often used to make the binder.
Why Roaches Eat Paint Binder
The binder is the component that holds the pigment together. Certain colors and tones are also achieved because of animal-based ingredients. The most common binder and pigment ingredients are:
- Ox gall
- Potato starch
- Snail glands
- Lice blood
- Vegetable oil
- Animal fats
Despite being mixed with chemicals, cockroaches can detect these ingredients in paint. They’re yummy substitutes when the pests are low on food. The only kinds of paint that cockroaches actively dislike are those made completely free of any animal-based products. These are known as vegan paints.
Cockroaches are particularly attracted to paints that contain animal fats, like oil paint. They are fond of substances that can be easily stored. According to the Annual Review of Entomology, the insects’ body fat plays a huge part in their survival capabilities.
The fat body of a cockroach is a set of tissues composed of cells that serve multiple purposes in the cockroach’s day to day life. Fat bodies help store nutrients as well as metabolize them.
Through it, cockroaches can eat paint and acquire the nourishing substance within it. Fat bodies also store fat better than other substances, so when a cockroach consumes paint with animal fats, the fat storage lasts longer. This is a crucial element of survival if the cockroach will be going a long time without eating.
Is Paint Harmful for Cockroaches to Consume?
Eating paint does not harm cockroaches in the slightest. That’s because cockroaches have the best genome suited for consuming toxic material.
According to North Carolina State University, cockroaches have the second-largest genome of any insect. A genome is the complete set of genetic information an organism can have. It contains all the information one needs to function, like the CPU of a computer or a car engine.
Cockroaches have always loved bacteria-filled, unpleasant environments. Before humans became the dominant species and left empty soda cans lying around on desks, cockroaches would often consume plants that contained toxic substances. Constantly associating with these plants caused cockroaches to evolve their genes to the point where they could digest harmful matter.
Genes are hereditary, meaning that cockroaches that developed this ability in the past will hand it down to the cockroaches of today. Modern-day roaches consume just as many, if not more, toxic material as their ancestors.
The human food they scavenge is often chemically altered and would be harmful to other animals. A cockroach’s metabolism, by nature, knows how to process all the toxins in human foods so that it doesn’t harm the cockroach. So strong is the cockroach genome that even insecticides don’t outright kill these pests.
Paint is a walk in the park compared to insecticides. That’s why they have no problem using it as a food source, despite paint being a non-food substance. The kinds of paints cockroaches are commonly attracted to are:
These are used in paintings and murals. They are also attracted to emulsion paint, which is used for walls. The one type of paint they seem to like the least is enamel paint. This is an air-dry paint used for concrete, refrigerators, engines, and nails.
Does Paint Repel Cockroaches?
Paint does not outright repel cockroaches. If the paint does not contain any substance a cockroach can eat, they will ignore it.
Some paints contain active cockroach-repellent ingredients like insecticide. These draw the cockroaches in for easy exterminating. Most anti-cockroach paints have no fumigation effect, so it’s safe to paint in human environments. Those kinds of paints are used for areas that cockroaches usually inhabit, such as:
- Kitchen cabinets
- Laundry rooms
How Can I Use Paint to Repel Cockroaches?
Is vegan or insecticide-infused paint something you can’t find or don’t wish to use? Then there are many things you can mix with paint to repel cockroaches.
Many herbs, oils, and spices are natural cockroach repellents. When mixed with paints, they will ensure that cockroaches have a harder time surviving in your household.
- Tea tree oil
- Eucalyptus oil
- Lavender oil
- Cypress oil
- Peppermint oil
- Oregano oil
- Citronella oil
- Rosemary oil
- Cedar oil
- Catnip oil
- Lemongrass oil
- Yarrow oil
Herbs and Spices
- Apple mint
- Bay leaves
- Ginger mint
- Basil mint
- Water mint
- Pandan leaves
- Garlic (best for painting the exterior of the house)
Essential oils and natural remedies are often criticized for being associated with pseudo-sciences and old wives’ tales. Luckily, however, the Tehran University of Medical Sciences published a study confirming the effectiveness of essential oils in repelling and even exterminating cockroaches.
The study used 5 types of essential oils: rosemary, oregano, yarrow, eucalyptus, and mint. Here is a table to give you an idea of how much of each essential oil to use in paint. This presents the effectiveness of each oil at different concentration levels:
|Oregano||30% 15% 10% 5% 2.5%||96.5% 96.8% 96.03% 98.8% 99.1%|
|Eucalyptus||30% 15% 10% 5% 2.5%||27.7% 33.3% 43.2% 51.7% 49.8%|
|Mint||30% 15% 10% 5% 2.5%||63.3% 60.1% 59.01% 68.8% 63.3%|
|Yarrow||30% 15% 10% 5% 2.5%||86.7% 84.2% 83.3% 92.8% 79.3%|
|Rosemary||30% 15% 10% 5% 2.5%||86.2% 94.5%|
As seen by the table above, different concentration percentages affected the repellency of each oil.
Which Oils To Use?
Eucalyptus oil is the least effective. When used, though, it is better to use a lower percentage of concentration, as 5% was more effective than 30%.
Mint oil caused a 59.1 to 68.8% repellency, which means that the concentration level only affects the repellency by an insignificant amount.
Much like eucalyptus, yarrow oil showed the highest repellency effect when only 5% was used. That means only a little should be used when being mixed with paint for the maximum amount of effectiveness.
Oregano oil varied between 96.03 and 99.1%, meaning that the concentration levels matter very little regarding its effectiveness. The study also proved that oregano oil is the best essential oil to mix with paint if you want to ward off cockroaches.
While rosemary oil was only tested with 2 concentration levels, the study found that rosemary was the most toxic substance for cockroaches. It caused a 100% mortality rate in the cockroaches after only 24 hours of exposure.