There are all different kinds of flies in the UK and, most of the time, they do not cause us any problems; from the fruit fly to the blue bottle fly, their numbers literally number thousands. But why do flies become a nuisance and what can we do about it?

The life cycle of a fly

In general, eggs are laid in moist or rotting organics matter, from household rubbish, to compost and manure. Once hatched, it really depends on the weather and temperature as to how long it takes the fly to reach maturity – the warmer the temperature, the quicker they will mature.

It is no surprise that a fly infestation quickly takes hold when you know that one adult female fly can lay 900 eggs in her life time – which, in most cases is a 1 to 3 month life expectancy!

Add to this the ability of all flies to fly some distance, moving quickly from one breeding ground to another. If you suddenly find a room full of blue bottle flies at home, it means that close by a small animal, rodent or bird has died, with an opportunistic female fly laying her eggs on the corpse.

Flies indoors

Flies of any kind are not picky about the kinds of food they eat and so, they will frequently make their way in to the home looking for a food source. Once they are indoors, they become active, excited and agitated by all the smells of food that they can feed on.

Flies suck up and also defecate on it, which is why if you know a fly has landed on some food left in the open, it will have been contaminated and is best thrown away. This spreading of bacteria and germs is the reason why finding the source of a fly infestation in or around the home is imperative in getting rid of it!

Can flies really make us ill?

There have been cases of gastroenteritis, salmonella, cholera and typhoid – as well as the distinct possibility of intestinal worms – as a result of a fly infestation. One or two flies, newly arrived through the back door may not be a problem but, an infestation where you home seems to be over-run means illness is a real possibility.

Preventing fly infestations

To a certain extent, some fly infestations can be prevented. If you are leaving food out, it should be well covered and make sure that hygiene and cleanliness is enforced throughout the home, as well as outside the property too.

Making sure that bins have well-fitting lids and that all refuse is placed in the bin immediately, will also help in keeping at bay any possible fly infestations. Compost bins are a great addition to any home, but siting it away from the property and also ensuring that it is well covered, with a lid if possible but using the plastic barrels, and that only the right waste is placed on it.

Although flies like all rotting food, protein rich food such as meat is a firm favourite.


Finding the source of any fly infestation is imperative and treating flies indoors will be a constant action as more and more flies hatch from the eggs laid by females.

Once the source has been found, it can be removed and the area cleaned; this will have immediate impact.

There are remedies that can be bought in supermarkets etc. and can be useful for the occasional fly but, if it seems that you have many blue bottles, houseflies or other flying, two winged insect in your home, then you need the expert help of Mr Pesty – call us to find out more!