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Name: Mary
Location: N/A
Country: N/A
Date: N/A

Over the past week, out house has been infested with big houseflys! I am killing 10-15 in one swipe! It only tends to be during the day with the light coming through the windows, but it been going on for 3 days now and they just keep coming! Where are they coming from and why are they so huge? I feel like maybe I've been keeping a fithly house, but I know it's clean. Please help me to understand what is going on. This is the first time I have ever seen so many in my house.

Mary Jo,

The way to deal with any insect infestation is first to get rid of the adults and then remove the children and the place they will/can develop.

Seeing that you are swatting 10-15 per swipe of the adults, you have step one in progress. Continue removing the adults as you find them and you lessen their opportunity for reproduction.

The second mode of attack is to remove any and all opportunities for development of their young. If you recently brought into the house any organic materials from outside, or anything containing a niche where the young can develop, return it to the outdoors. For potted plants you may have brought again indoors, replace the potting soil with new soil from a garden center. Be sure to dispose outdoors any and all plant medium where the flies may have laid their eggs. Mulch also is a breeding ground for flies and their larvae. Be sure to be extra conscious to remove any potential food source. Bananas and any fruit should not be left out on the counter (store it in a Rubbermaid type container. Be sure not to leave open access to any source of water (don't leave glasses in the sink holding water, for example.) Assuming you get rid of all the niche/food sources and you continue to kill adults as they emerge, you will see the population drop to zero.

Finally, make sure any access to the outdoors is sealed. Both in your living area, as well as attic or cellar, make sure the insects are not able to enter in seek of warmer quarters for the winter.

Good luck.

Thanks for using NEWTON!

Richard R. Rupnik

There are many species of flys, different sizes. If you have a "sudden" invasion of flys they are probably maturing from some breeding spot that has gone unnoticed for a few weeks, somewhere in or very near your house, in a hidden spot that you overlooked, was something organic that flys could lay eggs on and the larvae feed and mature. If there is a way for them to come in from outside, at this time of year, they will do that; if not then the source was probably somewhere inside; no matter how well you clean no one is perfect and it doesn't take much. Once this "hatch" is gone - you've killed them all - if there is no new place for them to lay eggs you probably have nothing more to worry about.

J. Elliott

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