US:THE INTREPID hunter stalks his prey, patient, swift, sure. (Sorry ladies, hunting is for men, real men.) Suddenly there it is, ready to fall victim to the mighty weapon he wields. He strikes out, but somehow the old enemy escapes! The fly swatter misses its mark and the fly buzzes away, the great hunter once again failing to make the kill, writes Dick Ahlstrom, Science Editor.
But why one might ask, are those dirty beasts so very difficult to hit? Why do they so often escape? Scientists from no less than the California Institute of Technology in Pasadena have been studying what allows flies to elude the swatter time and time again, and have finally revealed the answer, publishing it in the peer reviewed journal Current Biology. The little blighters easily see us coming with their 360 degree vision and then react much faster than we do.
They spot the approaching swatter, then choose an optimal escape route and reposition their body to launch into the wild blue yonder in any direction they choose, and do all this in about two-tenths of a second.
Cal Tech's Prof Michael Dickinson used high-speed video recordings of flies evading an approaching swatter. He found that these insects are purpose-built escape artists. They retain the ability to fly (as you might expect of a fly) off in any direction they chooses no matter how their body or wings are orientated relative to the perceived threat.
This allows the bug to clear out long before the blow actually falls.
"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," Prof Dickinson said.
"This illustrates how rapidly the fly's brain can process sensory information into an appropriate motor response." Ah, but the mighty hunter applies reasoning to the situation and (thanks to a bit of advice from Prof Dickinson) develops a new approach.
You send the swatter on its deadly way, but aiming to strike not where the fly currently sits but where you think it will be a fraction of a second later.
Of course you have to reset your hunting instincts, honed over the eons thanks to evolution, and first find the bugger again so you can have another go. And this time, maybe, just maybe, you will have a trophy to hang on the wall, or even one to roll up in a tissue and throw in the bin.