Do coffee grounds keep bugs away?

Can coffee grounds provide extra protection and deter insects from your home?

coffee grounds in mug with plants in the back ground
(Image credit: Getty images / Wachiwit)

Coffee grounds are useful far beyond your morning caffeine kick. Burning coffee can get rid of mosquitoes, so it is not surprising that they help dispel other unwanted bugs as well.

During the warmer months, we spend a lot more time outside and often have our windows and doors open. Unfortunately, this can attract more bugs inside.

Below we look at the different ways burnt coffee grounds can be used to ensure your home is bug-free not just during summer but all year round.

Do coffee grounds keep bugs away?

We already know that coffee is able to boost plant growth indoors and out, and can even help with cleaning your furniture. Below, experts share their views on how effective coffee grounds are for repelling bugs.

coffee grounds in a portafilter on top of coffee beans

(Image credit: GettyImages)

How effective is burning coffee grounds?

Guy Halverson from pest control company Truly Nolen says that there have been a number of studies to test the effects of burnt coffee grounds on different bugs. ‘We have seen varying degrees of effectiveness in using burnt coffee grounds,’ he comments. ‘Scientific research has shown it is highly effective against mosquitos, cockroaches, and ants.’

This is because coffee grounds contain compounds such as caffeine and diterpenes, which can act as a natural insecticide. They also work by masking the scents that attract bugs, this makes it harder for the bugs to locate their targets. 

Coffee grounds have a strong scent but become even more potent when burned. The strong, powerful scent contributes to a smoldering effect that will fight off pests.

Guy Halverson
Guy Halverson

Guy Halverson joined Truly Nolen in June 2019 as a manager-in-training. 2020 promoted to Branch Manager in Santa Fe, New Mexico. According to the company, he “has worked in the pest control industry since 1974 when, at the age of 16, he was the youngest licensed pest control operator in the state of Texas.

How to use coffee grounds to get rid of bugs

There are a number of ways you can use burnt coffee grounds as a bug repellent, and you may find it helpful to try out different methods depending on the type of bugs you have.

However, before you can create these natural insecticides you will need to prepare the burnt coffee grounds. You can buy fresh ground coffee bags from Amazon either already brewed or burnt.

To burn your coffee grounds, use them as you would normally when brewing your coffee to drink, but then brew the same grounds a second time. After a double brew, toss the grounds in a dry pan to ensure the fragrance is enhanced and extracted from the coffee.

Pest control expert and owner of On Demand Pest Control, Vincent Luca says that once prepared, you can use the burnt grounds in a variety of ways including in sprays, liquid solutions, and in a dry form that can be sprinkled on the ground.

Vincent Luca
Vincent Luca

Owner and founder of On Demand Pest Control, providing extermination services for both residential and commercial properties throughout South Florida with over 27 years of experience.

Use different methods for different bugs

coffee grounds and egg shell in a bowl in the garden

(Image credit: Alamy)

A.H David, owner of Pest Control Weekly says that the idea of using coffee grounds to repel bugs is quite popular, but the effectiveness of coffee grounds as a pest deterrent is somewhat mixed, depending on the bug.

  • Ants and slugs – Coffee grounds can be effective in deterring certain types of pests and are certainly worth trying as a method to get rid of ants and get rid of slugs. Both of these creatures dislike the strong smell of coffee. So, spreading coffee grounds in areas where you notice ant trails or slug activity will help 
  • Mosquitoes, bees, and wasps – Coffee grounds can also be used as a DIY repellent for flying pests like mosquitoes, and bees, and for getting rid of wasps. By burning the coffee grounds in the same way you would burn incense helps keep these bugs away as they do not like the smell produced by the smoke.
A.H David

A.H David is the co-founder and editor-in-chief of Pest Control Weekly. By hobby, he is a gardener and has experience dealing with all types of pests found in backyard gardens. His goal is to provide well-researched and authentic information about pests from his own experiences.


Can you burn coffee grounds in a wood burner?

Yes, you can burn coffee grounds in a wood burner. Coffee logs are logs of compacted coffee grounds that can be burnt in wood burning and multi-fuel stoves, as well as biomass boilers. The coffee grounds not only burn well when dried out, they supposedly burn hotter and longer than wooden logs and give off a subtle aroma too.

Burnt coffee grounds can act as a deterrent for some bugs and insects, however, they should be used wisely and as part of a broader approach to pest control.

In addition to repelling pests, coffee grounds can also be beneficial for the soil. They are rich in nitrogen and can therefore be mixed into the soil or added to your compost pile as a green compost material. However, keep in mind that coffee grounds can make the soil more acidic, which isn't suitable for all plants.

Seraphina Di Mizzurati
Contributing Editor

Seraphina is a contributing editor at Homes & Gardens, writing Solved features on organizing and storage. She loves to decorate and also grow her own produce from her home in London. Her previous experience includes working at Women's Health and Fabulous Magazine.