The crafty fly

You position your sunbed so it is nicely in the shade, lie down ready for a pleasant afternoon nap and just as you are about to nod off a fly comes to land on your face. You waft it away only to find the cheeky bugger returning time and again to irritate you some more. Any chance of sleep is gone as you struggle to rid yourself of the nuisance.

Even with a fly swatter or a rolled up newspaper to hand, my success rate at swatting flies is abysmal. I hover over the fly and then just as I pounce - the fly escapes.

Scientists from the California Institute of Technology have now explained why my technique doesn't work.

Instead of just taking off when they see an object hurtling towards them, flies carefully plan an escape in milliseconds. A fraction of a second before a fly springs into the air, it will alter its body position so that it is properly prepared to jump in the right direction.

If the blow looks as if it is coming from behind, the fly will move its middle legs forward a little and lean back, so it is ideally positioned to jump forwards into the air and away from the threat. For a threat from the front, it will move its legs backward and leap that way. For sideways threats, it will keep its legs still and lean to the other side to get ready for a lateral escape.

The entire process of calculating the direction of the threat and preparing the body takes just one tenth of a second, and it will have flown away within two tenths of a second.

The right approach is therefore to aim not at the insects themselves because they are extraordinarily good at anticipating where exactly your blow will land. It is best to aim a bit forward of the fly's starting position, to anticipate where it is going to jump when it first sees your swatter.

Here are three further suggestions that might help me achieve a higher success rate.

This method never fails: hold the swatter handle with one hand then, with your other hand, pull the neck back away from the fly and release. The spring action is too quick for the fly and you are guaranteed an accurate swat.

I have realised after successfully swatting thousands of flies why the fly swatter is better than using a rolled up newspaper.It is because a fly can still see through a flyswatter's mesh/lattice work and does not rate it as serious a threat as a rolled up newspaper which cuts out the light.

Never try to hit the fly directly where it sits. Simply clap hands together about 5 cm above where the fly positioned. It flies into the path of the hands as it can only judge the threat from one direction. Always works for me. Oh yes, have soap to hand for washing afterwards!

That was the technique my father used when he came to visit us. It was obviously successful for him because he was surrounded by dead flies at the end of each day.