Flies
Homemade fly trap and home remedies for flies: what works?
A homemade fly trap is quick to make: a bottle or bowl with something that smells, and an opening that flies can get into but struggle to get out of. Whether it noticeably reduces the flies in your house has not been studied, and for the popular home remedies against flies we know of no research showing they keep flies out; at most, concentrated basil oil kept house flies at a distance in laboratory tests (Environmental Science and Pollution Research, 2021). What does help is tackling the cause: covered bins, fly screens on open windows and clearing up where flies breed (British Pest Control Association, BPCA). Below, each home remedy and what it does.
In this article
How do you make a fly trap for house flies?
You can make a fly trap with a plastic bottle: cut off the top, turn it upside down into the bottom half like a funnel and put something that smells in the bottom, such as sugar water or a piece of overripe fruit. Flies find their way in through the funnel and struggle to find the way out. How many house flies it catches has not been studied, and it draws flies to wherever it stands, so do not put it next to the table.
What bait attracts house flies best?
The best bait for house flies is something that smells of what they look for: rotting and fermenting food. House flies breed in manure, kitchen waste and fermenting vegetables (University of Florida), so sugar water, overripe fruit or a fermenting liquid will lure them. Which bait catches the most in a homemade trap has not been studied.
Which home remedies against flies are there, and what do they do?
Home remedies against flies work in two ways: with a smell that is meant to put flies off, or with a bowl or bottle that lures flies and holds them. For neither do we know of research showing they reduce the number of flies in a house.
| Home remedy | What it does | What is known |
|---|---|---|
| Vinegar with washing-up liquid in a bowl | the smell lures; the washing-up liquid makes a fly that lands sink | no research known |
| Bottle trap with sugar water | the smell lures; flies struggle to find the way out | no research known |
| Cloves in a lemon or orange | strong smell on the table | no research known |
| Basil, mint or lavender on the windowsill | the smell of the plant | basil oil kept house flies at a distance in laboratory tests (Environmental Science and Pollution Research, 2021); for a plant on the windowsill we know of no research |
| A bag of water, with or without a penny | the reflection is said to scare flies off | no conclusive research; a review found no evidence that it works (Insects, 2021) |
| A fan | the airflow makes landing harder | no research known |
Does a bag of water or a penny keep flies away?
There is no good evidence that a bag of water keeps flies away: a review found no conclusive proof that bags of water scare flies off (Insects, 2021). The idea is that the reflection in the water confuses flies; whether that keeps them away from a door or a table has not been shown.
Which smell do flies hate the most?
Which smell flies hate most is not well known. Cloves, lemon, basil, mint and lavender are often mentioned. Only for concentrated basil oil do laboratory tests show that house flies stay away (Environmental Science and Pollution Research, 2021); that a smell in the house keeps flies outside has not been shown.
Does vinegar and washing-up liquid catch flies?
Vinegar with washing-up liquid can catch some flies: the smell lures, and the washing-up liquid makes a fly that lands on the liquid sink. How many house flies it catches has not been studied; for fruit flies, see our homemade fruit fly trap.
What actually helps against flies in the house?
What actually helps against flies in the house is tackling the cause: bins with tight lids, away from doors and windows, food covered, fly screens on windows and doors you keep open, and finding where the flies breed; for a few flies indoors a fly swat or sticky fly paper (BPCA). The full approach is in our guide how to get rid of flies in the house.
Sources: British Pest Control Association, flies; University of Florida, house fly.
