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6 Types of Pests That Coffee Grounds Repel

Used Coffee Grounds From Espresso Machine.

Nothing beats brewing your favorite cup in the morning using your most precious coffee grounds. The scent and the vibe make you look forward to waking up every day and getting ready for work. After brewing and drinking your favorite cup of joe, you might think the coffee grounds are ready to be disposed of. But did you know you can actually use them to repel pests?


Most homeowners love using coffee grounds to repel pests because they are eco-friendly and not toxic to the environment. Moreover, several pests are not fond of coffee’s intense scents.

Learn more about the following in this guide:

  • Why pests hate coffee grounds.
  • Specific coffee grounds that can absolutely repel pests.
  • How you can use coffee grounds as natural pest repellents.

There’s no need to throw away used coffee grounds after reading this article. And with our easy step-by-step solution to using these, you’ll immediately be up on your feet, deterring all kinds of pests at your home.

Why Pests Hate Coffee Grounds

Closeup Detail Of Coffee Ground In Wooden Bowl

Aside from the fact that coffee has intense smells that could be dangerous to most pests and even wild animals, their two main chemical compounds make coffee grounds effective insect repellents.


For people, caffeine makes everything better. It gives them the energy boost they need to power through the day. Plus, caffeine helps people stay awake for a long time. But to pests, this chemical substance is toxic and dangerous.

Caffeine can cause the following in pests and animals:

  • Irregular heartbeat
  • Higher blood pressure
  • Loss of muscle control
  • Muscle spasms and shaking
  • Seizures

And when pests ingest too much caffeine, it can lead to an overdose that could kill them.


Some plants contain diterpenes and serve as their self-protection strategy. This compound prevents herbivores and insects from eating the plants. Unfortunately, diterpenes are toxic to pests because they affect their hormones, causing abnormalities when growing. This chemical can also cause pests to feel weak, restless, and bloated. And in worst cases, diterpenes can kill these tiny animals.

6 Types of Pests That Coffee Grounds Repel

While coffee grounds are effective against various types of pests, insects, and animals, it’s better to know what specific species these coffee grounds will repel successfully.

We created a list of all the pests coffee grounds can deter and effective hacks on how you can use these aromatic grounds.

1. Ants and Beetles

Macro Close-Up Of A Wood Ant

Ants are the perfect examples of pests who mainly use their senses of smell to look for food. It serves as their internal map because their eyes don’t work as much as ours.

When coffee grounds are sprinkled in your garden or pot plants, they can disrupt the ants and confuse them regarding their current path. The scent also messes with the ants and will cause them to stay as far away as possible from the potted plants with coffee grounds.

Like ants, coffee grounds are also dangerous to beetles. Spreading them on your garden’s soil around the beetles’ targeted plants will make them want to stay as far away as possible.

2. Caterpillars

Three Monarch Caterpillars Eating Milkweed

Caterpillars are also effective victims of coffee grounds. But unlike the method used when killing ants, coffee grounds should still be dissolved in warm water. Imagine how a cup of weak tea looks. That should be exactly how your coffee ground mixture looks. After letting the coffee grounds and water cool down, transfer it to a spray bottle and spray directly on the plants.

You can also spray the ground where the plants are, soaking the soil and becoming even more effective in removing caterpillars.

3. Fleas and Flies

A Cut Apple Has Attracted Fruit Flies To Feed On It

Coffee grounds are also effective against fleas and fly infestations. You can even scrub used coffee grounds on your pet’s fur while bathing them. But you must rinse your pet well after applying coffee grounds so they won’t feel irritated.

When it comes to flies, it’s a fact that they prefer sweet-tasting substances. However, because coffee grounds are on the bitter side, most flies are not fond of their scent and will try to avoid areas where you place them. Moreover, some flies can smell the coffee grounds’ caffeine and diterpenes, which are harmful to them.

4. Mosquitoes

Little Girl Has Allergies With Mosquitoes Bite And Itching Her Leg.

Mosquitoes, especially mature ones, are scared of used and fresh coffee grounds. Most homeowners love sprinkling coffee grounds around trees and plants in their gardens and areas near their pooled water because the pooled water serves as their breeding ground. Burning coffee grounds is also effective in deterring mosquitoes away from your home.

A mixture of water and coffee grounds can help repel mosquitoes because of the following reasons:

  • Mosquitoes don’t lay their eggs in coffee-smelling pooled water.
  • Used coffee grounds can prevent young mosquito larvae from growing and developing.
  • No mosquito larvae can become immune to coffee grounds, unlike the pesticides you frequently use.

5. Rodents

Squirrel Red Fur Funny Pets Autumn Forest On Background Wild Nature Animal Thematic (Sciurus Vulgaris, Rodent)

Coffee grounds are not the best substances to deter bigger pests like rodents, chipmunks, and squirrels. But a few researchers have revealed that these pests still try to avoid coffee. They dislike the gritty texture they feel underneath their paws. Plus, rodents are smart enough to smell that coffee contains dangerous chemicals.

6. Slugs and Snails

Spanish Slug (Arion Vulgaris) Invasion In Garden. Invasive Slug. Garden Problem. Europe.

Coffee is definitely toxic to slugs and snails. They will not touch or eat anything that smells like coffee because these animals know it will kill them. Moreover, if you directly spray the concentrated coffee solution on a slug or a snail, expect them to die instantly.

The caffeine in coffee makes the heart rate of snails and slugs beat faster, which can kill these animals within 96 hours.

Ways To Use Coffee Grounds To Repel Pests

Ground Coffee With Burlap Bag On The Wooden Table In The Kitchen.

For the best results, fresh coffee grounds are always the better option because of their high diterpene and caffeine concentration. Used coffee grounds have decreased potency because they already lose their freshness, but they are still effective. These easy hacks can help you use coffee grounds to deter common pests:

  • Sprinkling coffee grounds on your garden soil
  • Spread coffee grounds on plants or trees you want to protect to create a slug and snail barrier.
  • Place coffee grounds around your pet bowls to prevent ants from entering your pet’s food and water.
  • Burn your coffee grounds and place them in a bowl to deter bees, yellow jackets or wasps, and mosquitoes.
  • Create a coffee and water solution and spray the mixture on the ground and plants.

Coffee Grounds Can Help Keep Pests at Bay

Unrecognisable Woman In Casual Clothing Holding A Box Of Used Coffee Ground

Coffee grounds are versatile substances used for various purposes. Aside from waking you up, they work well as effective fertilizers and pest repellents. The secret is knowing what to do and where to sprinkle them to deter all types of insects and make your home pest-free. Because of coffee’s caffeine and diterpene content, most pests, including bugs, rodents, flies, fleas, and mosquitoes, try to stay away.

Frequently Asked Questions

Are Coffee Grounds Effective Against Roaches?

Roaches are one of the only pests that are attracted to coffee grounds. Some homeowners are troubled over cockroaches nesting in their coffee makers because these pests love the bitter aroma of coffee.

Can You Still Use Coffee Grounds To Kill Roaches?

You can still use coffee grounds to outsmart roaches and try to kill them.

Follow this step-by-step hack:

  1. Place coffee grounds in a bowl or cup.
  2. Pour water into a glass jar until halfway.
  3. Place the cup with coffee grounds inside the water-filled glass jar. This will serve as your homemade trap.
  4. Leave the trap in an area commonly visited by roaches. These pests will likely drown as they try to reach for the coffee grounds in the cup.

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