Updated: April 12, 2023

Earwigs, also known as pincher bugs, are common household pests that can be a nuisance. These small, dark insects have pincers on their rear end and are often found in damp areas such as under rocks, logs, and in gardens. While they do not pose a threat to humans or pets, their presence can be unsightly and annoying. There are many methods of repelling earwigs, but one natural solution that has gained popularity is the use of coffee grounds. In this article, we will explore the effectiveness of using coffee grounds to repel earwigs.

The Science Behind Coffee Grounds as a Repellent

Coffee grounds contain several chemical compounds that are known to repel insects, including earwigs. One of these compounds is caffeine, which has been shown to have a toxic effect on insects. When ingested in high doses, caffeine can cause paralysis and death in insects. Another compound found in coffee is diterpenes, which have been shown to repel insects such as ants and cockroaches.

There have been several research studies conducted on the effectiveness of coffee grounds as an insect repellent. One study published in the Journal of Pest Science found that coffee grounds were effective in repelling several species of insects, including earwigs. The researchers concluded that the caffeine and other compounds found in coffee grounds were responsible for the repellent effect.

How to Use Coffee Grounds to Repel Earwigs

To use coffee grounds as an earwig repellent, there are a few steps you can take:

1. Collect used coffee grounds: Collect used coffee grounds from your morning cup of coffee or ask your local coffee shop for their used grounds.

2. Dry the coffee grounds: Spread the coffee grounds out on a baking sheet and allow them to dry completely.

3. Apply the coffee grounds: Sprinkle the dried coffee grounds around the perimeter of your home and garden. Pay special attention to areas where earwigs are likely to congregate, such as under rocks or near plants.

4. Reapply regularly: To maintain the repellent effect, reapply the coffee grounds every few weeks or after rainfall.

Other Benefits of Using Coffee Grounds in Gardening

In addition to repelling earwigs, using coffee grounds in gardening practices has several other benefits. Coffee grounds are a nutrient-rich soil amendment that can help improve soil structure and fertility. They also contain compounds that can help control pests such as slugs and snails and attract beneficial earthworms.

Using coffee grounds in gardening practices is also an environmentally friendly option. By reusing an otherwise discarded waste product, you can reduce your environmental impact and contribute to a more sustainable future.


While there are many methods of repelling earwigs, using coffee grounds has proven to be an effective natural solution. By understanding the science behind how coffee grounds repel insects and how to use them effectively, you can keep your home and garden free from these pesky bugs without relying on harmful chemicals.

In conclusion, we encourage you to try using coffee grounds in your gardening practices as a way to repel earwigs and contribute to a more sustainable future.