The brains of flies are wired to avoid the swatter, US 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.

"This illustrates how rapidly the fly's brain can process sensory information into an appropriate motor response," said Dickinson, whose research appears in the journal Current Biology.

Dickinson's team studied this process in fruit flies using high-speed digital imaging equipment and a fancy fly swatter.

In response to a threat from the front, the fly moves its middle legs forward, leans back and raises its back legs for a backward takeoff. If the threat is from the side, the fly leans the other way before takeoff.

The findings offer new insight into the fly nervous system, and lends a few clues on how to outsmart a fly.

"It is best not to swat at the fly's starting position," Dickinson said. Instead, aim for the escape route.

Dickinson, a bioengineer, has devoted his life's work to the study of insect flight. He has built a tiny robotic fly called Robofly and a 3-D visual flight simulator called Fly-O-Vision.

蚊子的大腦是網(wǎng)狀的，以避免被捕殺，美國(guó)研究者周四說(shuō)。動(dòng)作按相反方向逃跑，以確保

就在出現(xiàn)危險(xiǎn)苗頭時(shí)，這種昆蟲(chóng)就會(huì)調(diào)整自己的起飛準(zhǔn)備，確保徹底逃離，研究者們?cè)诎l(fā)現(xiàn)中稱，這可以解釋為什么蚊子這么容易逃離人類敵人的拍打。

“這種運(yùn)動(dòng)非常之快，大約只用200毫秒，而在這么短的時(shí)間里，這種動(dòng)物可以確定威脅的來(lái)源并刺激適當(dāng)?shù)囊幌盗羞\(yùn)動(dòng)，以放置自己的腿和翅膀”，加州科技大學(xué)的Michael Dickinson 在一份發(fā)言中說(shuō)。

“這說(shuō)明了蚊子可以快速地處理敏感信息，作出適當(dāng)?shù)倪\(yùn)動(dòng)響應(yīng)”，Dickinson說(shuō)，其研究發(fā)表在《當(dāng)代生物》期刊上。

Dickinson的研究團(tuán)隊(duì)使用高速數(shù)字圖像設(shè)備和有趣的捕蚊拍研究了果蠅的處理反應(yīng)過(guò)程。

對(duì)來(lái)自前方威脅的反應(yīng)，蚊子向前移動(dòng)其中間的腿，向后傾斜，并抬起后腿進(jìn)行后向起飛。如果威脅來(lái)自側(cè)面，蚊子就在起飛前傾向另一側(cè)。

該研究發(fā)現(xiàn)對(duì)蚊子的神經(jīng)系統(tǒng)有了新的看法，為怎樣智勝打敗蚊子提供了線索。

“最好不在蚊子的啟動(dòng)位置去打它”，Dickinson說(shuō)。而應(yīng)該瞄準(zhǔn)它的逃跑路線。

生物工程師Dickinson致力于昆蟲(chóng)飛行的研究。它研制了一個(gè)微型機(jī)器人昆蟲(chóng)叫Robofly和一個(gè)名為Fly-O-Vision的3D視覺(jué)飛行模擬器。