Why is it so hard to swat a fly?

The insects adjust their position at the mere hint of a threat, finding shows

CHICAGO - The brains of flies are wired to avoid the swatter, U.S. researchers said on Thursday.

At the mere hint of a threat, the insects adjust their preflight stance to flee in the opposite direction, ensuring a clean getaway, they said in a finding that helps explain why flies so easily evade swipes from their human foes.

"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," Michael Dickinson of the California Institute of Technology said in a statement.

Link: http://www.msnbc.msn.com/id/26443667/