It is a frustrating experience familiar to us all: an irritating, buzzing housefly that easily avoids our best attempts to swat it.

The perfect swatting strategy, however, has now been revealed by scientists who have identified why the insects are so good at evading rolled-up newspapers - and how they might be outwitted.

The right approach is 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,” said Michael Dickinson, of the California Institute of Technology, who led the study.

In the research, published in the journal Current Biology, Dr Dickinson's team used high-resolution, high-speed imaging technology to examine how flies move to avoid impending threats. Instead of just taking off when they see an object hurtling towards them, the insects 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.

“We were surprised to find that long - in fly time - before a fly takes off in response to a predator or swatter, it plans the direction of the jump by making a rather complex series of postural movements,” Dr Dickinson said. “These movements are made very rapidly, within about 200 milliseconds, but within that time the animal determines where the threat is coming from and activates an appropriate set of movements to position its legs and wings. This illustrates how rapidly the fly's brain can process sensory information into an appropriate motor response.

“We also found that when the fly makes planning movements prior to take-off, it takes into account its body position at the time it first sees the threat. When it first notices an approaching threat, a fly's body might be in any sort of posture, depending on what it was doing at the time, like grooming, feeding, walking, or courting.

“Our experiments showed that the fly somehow ‘knows' whether it needs to make large or small postural changes to reach the correct pre-flight posture.

“This means that the fly must integrate visual information from its eyes, which tell it where the threat is approaching from, with mechanosensory information from its legs, which tells it how to move to reach the proper pre-flight pose.”

The scientists are now attempting to identify how the fly's brain makes these extraordinary calculations, to shed light on its neurophysiology.

“This is a rather sophisticated sensory-to-motor transformation and the search is on to find the place in the brain where this happens,” Dr Dickinson said. He added that he hoped the research might persuade people to give the insects a second chance by revealing their remarkable qualities.

He said that he wanted to make people “think before they swat”.

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