Rats hate the pungent smell of onions. Placing slices of fresh onion in places where rodents have been seen (e.g., basements, cupboards, behind the refrigerator) will effectively discourage them from returning.
Note: Onions must be replaced regularly—ideally daily—as they spoil quickly.
Flies
Flies dislike strong aromas, and onions act as a natural repellent. To get rid of them:
Chop the onion and place it in a bowl of water and a little vinegar.
Place it in the kitchen or by a window—flies will steer clear.
This is a natural way to protect your food and kitchen without the need for toxic sprays.
Bugs and Crawling Insects
Onions contain natural fungicidal and repellent compounds. Useful in the garden and home:
Chop an onion and scatter it around plants, pots, or on your windowsill to discourage insects.
Mix it with water and spray in areas where ants, silverfish, and cockroaches might enter.
Mosquitoes
The smell of onions is unbearable for mosquitoes. Simply:
Place half an onion with cloves stuck in it on a garden table, windowsill, or by your bed.
Onions mixed with water and a few drops of lemon oil can be used as a homemade mosquito spray.
This is one of the simplest and cheapest ways to prevent an evening on the patio from turning into a war on insects.
How to make a homemade pest repellent with onions?
Ingredients:
1 large onion,
500 ml water,
2-3 cloves (optional),
a few drops of essential oil (lavender, lemon, or eucalyptus – to enhance the effect and scent).
Preparation:
Chop the onion into small pieces.
Place it in a pot of water and simmer for 10-15 minutes.
Let it cool and strain.
Pour it into a spray bottle.
Add the oil and shake.
Use it on windows, doors, windowsills, and around areas where pests congregate.
Additional tips from my nana:
Don’t throw away onions after cooking! Place them in the garden or on the compost heap – they will repel slugs and rodents.
If you want to protect your dog or cat from fleas, don’t apply onion directly to the animals (it’s toxic to them!), but spray it on carpets, bedding, and corners where insects might hide.
You can wipe the inside of cabinets with onion decoction – it will repel moths and silverfish.
Summary
Onions aren’t just a kitchen ingredient. They’re a natural, cheap, and effective weapon against many household pests. My nana has been using them for years – and although they don’t smell like perfume, they work flawlessly. It’s worth a try before reaching for expensive, chemical remedies. Sometimes the solutions we’re looking for lie… in our own pantry.
