We have screens on doors and windows so don’t often see a fly inside the house. Occasionally one will sneak in when a door is open.

Years ago we used Raid branded fly spray but I noticed that it had lost its “knock down power”, so we switched to Mortein with “fast knockdown”; which sounded very impressive. I didn’t do any tests, but it seemed better.

Over the last couple of years I’ve noticed that Mortein seems to have lost its potency. I don’t like to fill the air with a massive cloud of spray as it suggests to do on the can but rather I chase the fly around, corner it in a smaller room and go for a direct hit with a smaller blast. I’ve noticed that a fly that’s been sprayed goes down as expected but later revives.

Last week I had two flies inside and decide to do a little test. I sprayed both as usual and when they were down put them in a plastic container with a clear lid . One of the flies got the normal dose and one got an extra dose. Several hours later one was dead and the other was up and flying about trying to get out of the container.

Conclusion: Fly spray is relatively save – even for flies.

A little while back they increased the size of the can; 25% more, or something like that. I know why. “They” know it doesn’t work very well, and by making the can longer it’s easy to hit the flies with it. Just make sure you swing it by the bottom end. If holding the other end and the top comes off, you could put it through a window.

I guess they don’t have much choice these days. Anyone could spray half a can into the air and then sit there breathing it in a toxic cloud for the next 5 minutes. By making it non-toxic, it’s also idiot proof. And we know the percentage of idiots in the population is rising rapidly.