Coffee grounds contain compounds such as caffeine and diterpenes that are effective in repelling insects, including mosquitoes and flies. When burned, these compounds are released into the air, creating an environment that is inhospitable to these pests.

Additional Tips:

• Boost the Effect: You can enhance the repellent effect by mixing the coffee grounds with bay leaves, which also have insect-repelling properties.
• Indoor Use: If using indoors, ensure proper ventilation to avoid smoke build-up.
• Regular Use: For best results, repeat this process as needed, especially during peak mosquito hours or when you notice flies are more active.

Conclusion:

Burning coffee grounds is a fantastic natural alternative to chemical repellents. Not only does it help in keeping away unwanted insects, but it also recycles your used coffee grounds and fills the air with a rich, aromatic scent. Give it a try and enjoy a more pleasant, pest-free environment in your home.