They're all rubbish these days. Seems like it stuns them but they get up and fly around again 20 minutes later. Might as well hit them with the can.

I like to have a couple of spiders in the house. They take care of the flies pretty effectively.

I saw a sciencey thing on this.

The warmer the weather the faster a fly can metabolise poison out of its system.

If hot enough the fly will recover, hence the get up and go again we see nowadays.

That, and the really good poisons aren't allowed any more.

So spray them to slow them down then whack them or vacuum them to finish the job before they get up again.

alasta:

 

I like to have a couple of spiders in the house. They take care of the flies pretty effectively.

 

Keeps the wife at bay too.

Thanks, all, for your input. 

Electric tennis rackets sound fun! Is it better to use forehand or backhand shots? Or, maybe, serves?

Rickles:

 

For a number of summers now I have used the auto-spray system ... firstly the Mortein spray definitely "kills them dead", and secondly the mist seems to set up a barrier that prevents flies etc coming in anyway (even with all doors open and I live across road from bush reserve).

 

Best of all, the hypoallergenic version doesn't seem to aggravate or harm people with hay fever, babies, or animals.  Also noticed that bumble bees are not affected by it 

 

Refills last a couple of years!

 

Which auto-spray system?  We have the "robocan" version, and that's 3 months on the "12hr" setting ... not a couple of years :-(

Also found that it's a deterent, rather than killing the bugs.

     >Which auto-spray system?<

Mortein ... I think they now call it Naturguard.  Got it from Supermarket.

I have better things to do than chase flies with either a can of fly spray or a electric racket. I've used the Robocan with the Expra refills for many years and it's great. It's a fly deterrent firstly (they often come in and do a u-turn back out the same way) and if they're undeterred they soon die - 10 minutes and they're usually doing the backspin somewhere.

I got sick of changing the expensive 9V battery so I rigged an old DC power supply to run it and put it on a $10 Elto timer from 6am to 8pm on the longer duration between pulses setting which gets about 12 weeks out of a refill which I buy from Bunnings for ~$25 a pair.

     >We have the "robocan" version, and that's 3 months on the "12hr" setting ... not a couple of years :-(<

I only use it when flies are extant ... so, summery days with French doors and/or front door open, and usually between 9am and 4pm-ish.  I never leave it on when out of the house or overnight, but definitely one refill canister lasts for over two summers for us (Thorndon, Wellington).

I'm not sure why this is, but all the locations I have lived around Wellington, we have almost never seen a house-fly. Blow-flies, yes from time to time.

Lived in New Plymouth as a kid, had heaps of house-flies there (probably not helped by my parents keeping chickens).

Rickles:

 

For a number of summers now I have used the auto-spray system ... firstly the Mortein spray definitely "kills them dead", and secondly the mist seems to set up a barrier that prevents flies etc coming in anyway (even with all doors open and I live across road from bush reserve).

 

Best of all, the hypoallergenic version doesn't seem to aggravate or harm people with hay fever, babies, or animals.  Also noticed that bumble bees are not affected by it 

 

Refills last a couple of years!

 

I just don't like the idea of living in a house that has poison automatically pumped into the atmosphere 24/7.

The problem is using these chemcials, flys have over time adapted to them and become immune. Yet they probably aren't good for human helth in teh long run. I never use fly spray, but then again I don't have a problem with flys. When there is a fly I use the bug zapper