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The Military Science

Fruit Flies, Fighter Jets Use Similar Evasive Tactics When Attacked 65

vinces99 writes: "When startled by predators, tiny fruit flies respond like fighter jets – employing screaming-fast banked turns to evade attacks. Researchers at the University of Washington used an array of high-speed video cameras operating at 7,500 frames a second to capture the wing and body motion of flies after they encountered a looming image of an approaching predator (abstract). 'We discovered that fruit flies alter course in less than one one-hundredth of a second, 50 times faster than we blink our eyes, and which is faster than we ever imagined.' In the midst of a banked turn, the flies can roll on their sides 90 degrees or more, almost flying upside down at times, said Florian Muijres, a UW postdoctoral researcher and lead author of the paper. 'These flies normally flap their wings 200 times a second and, in almost a single wing beat, the animal can reorient its body to generate a force away from the threatening stimulus and then continues to accelerate,' he said."

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Fruit Flies, Fighter Jets Use Similar Evasive Tactics When Attacked

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  • Anyone (Score:5, Funny)

    by mingot ( 665080 ) on Friday April 11, 2014 @02:34PM (#46727913)

    Anyone who has ever had these little bastards in their house could have told you how good they are at evading predators.

    • Re:Anyone (Score:5, Funny)

      by Anonymous Coward on Friday April 11, 2014 @02:56PM (#46728135)

      I especially hate when you are about to nail them mid air and they release decoy flares.
      That shit burns!

      • Re:Anyone (Score:5, Funny)

        by ByteSlicer ( 735276 ) on Friday April 11, 2014 @03:34PM (#46728473)

        Still, we're lucky they aren't carrying any Stingers.

        • It would actually be interesting to see if, given suitable advances in the design and construction of biomimetic robots, low-speed-but-lightweight-and-crazy-maneuverable becomes a viable strategy (presumably as a complement to a very high speed arsenal). Something with the maneuverability of a fly(especially a fly that also has a few small jets for bursts of thrust on maneuvers that exceed what its wings can provide) might well be able to walk right past missiles designed to intercept high speed conventiona
          • ...is that something with the brain the size of a fruit fly can discriminate between a predator and a non-predator, and react defensively.

            We really need to figure out how brains work, lol.

            • by mikael ( 484 )

              I'm not sure they can discriminate between a predator and non-predator. They go by smell to find food and partners. Just about anything that is a dark shadow or moves relative to the background is a potential predator - either they get squished or eaten,

              They do vision by a method called "optic flow". Imagine everything you see is projected onto a hemispherical dome (like one of those IMAX theaters). The only way you can tell how the camera is moving is whether the picture rotates around a single point, a pa

              • by fyngyrz ( 762201 )

                Imagine everything you see is projected onto a hemispherical dome

                Everything *we* see is put on our retina upside down and with a hole in it, and gets really crappy at the edges. Brainz. No wonder zombies like 'em. :)

            • We really need to figure out how brains work, lol.

              Or we just need to figure out how to maintain a blob of brain tissue for a long period... presumably you'd use a quorum of brains and have them vote on an action before you took it, majority rules to keep that instinctive speed

    • Yes, but they're also quite deaf. They seem oblivious to the vacuum cleaner. I've seen some fat, stupid fruit flies resting on my kitchen counter that *stay put* as their wings start to bend from the suction... Then, womp! down the hose and that's that.
      • I'm not sure if they are 'deaf' (and if they aren't, how much of their sensitivity-to-vibrations-in-fluid is actually 'hearing' and how much is 'touch' with their little sensory hairs) or if their range of stereotyped behaviors doesn't include predators that work by suction. There are some aquatic predators that are suction hunters, presumably becaues the fluid is denser; but nothing terrestrial comes to mind. If they evolved in absense of suction attacks, they presumably either are encountering something o
      • by mikael ( 484 )

        They are sensitive to sudden positive high-pressure air flow; flapping of a wing, motion of a bird. A continuous negative high-pressure air flow won't activate them.

    • Anyone who has ever had these little bastards in their house ...

      .. like in Virginia Beach [bbc.co.uk]?

    • Actually, my spiders don't have problems catching and eating them. Unless you meant MQ-1 Predators, that is. I've never observed a fly trying to evade those.
  • by Anonymous Coward

    "We discovered that fruit flies alter course in less than one one-hundredth of a second, 50 times faster than we blink our eyes"

    Almost as fast as a politician during an election campaign.

  • by wherrera ( 235520 ) on Friday April 11, 2014 @02:41PM (#46727977) Journal

    There is a variable angle change just after the initial turn away from the threat that allows the fly to be unpredictable. Otherwise the predator can predict the fly will evade directly away and anticipate where the fly will be. Very clever.

  • The flies need all the speed they can muster, to evade the even more deadly dead cat helicopter [youtube.com].

  • by Freshly Exhumed ( 105597 ) on Friday April 11, 2014 @02:52PM (#46728091) Homepage

    Dr. Baronovich: "You must think in Fruit Fly."

  • by Rich0 ( 548339 ) on Friday April 11, 2014 @02:54PM (#46728105) Homepage

    It sounds like they simply described the fly turning directly away from the predator and running, which is NOT what a fighter jet does (unless they just want to be shot down by a missile). At least, not unless they were already outside of their range (at that point, running is the best strategy).

    A fighter jet would make a sharp turn TOWARDS the attacker so as to cross his path at a sharp angle, which maximizes the velocity difference between them (velocity is a vector, and they are rapidly closing at an angle). This maximizes the amount of delta-V a missile would have to apply to intercept the aircraft, and in the event of a gunshot it maximizes the amount of lead angle that would need to be used (which is very difficult to pull off). Basically you try to ruin their opportunity to fire on you, so that you can get into a dogfight and hopefully get an opportunity to fire at them.

    See something bad and run away is a very intuitive strategy, and it probably makes a lot of sense in nature where predators have to make physical contact to hurt you. In a world of weapons where things like lead angles and enfilading fire come into play the optimum strategy may not be what a rabbit does when it sees a cat.

    • by Anonymous Coward on Friday April 11, 2014 @03:14PM (#46728297)

      Actually, I think the limit of the analogy was that both fruit flies and fighter jets use banked turns during evasive maneuvers. A banked turn is an obvious choice for a fighter jet, but when you get down to the size of a fruit fly, the aerodynamics are different and so it's interesting that this is still a preferred turning strategy.

      • by Rich0 ( 548339 )

        Actually, I think the limit of the analogy was that both fruit flies and fighter jets use banked turns during evasive maneuvers. A banked turn is an obvious choice for a fighter jet, but when you get down to the size of a fruit fly, the aerodynamics are different and so it's interesting that this is still a preferred turning strategy.

        I wouldn't take it for granted, but it makes a lot of sense in basic physics. Normally anything that flies has to produce a lift force directed upwards to counteract gravity. If you just turn it on its side the exact same force causes it to turn. So, while the wings could move in lots of odd ways, banking is a really simple solution to the problem of turning.

      • Makes sense to me - the primary function of the wings is to provide lift "up" - so for a more effective turn you pivot so that the maneuver is always "up" before you execute.

    • "There's a bunch of fighter jets in my pickled cucumbers!"

    • Check the list of agencies sponsoring the research. This is just a little game you have to play to do research in the US.
  • Finally, an excuse to play Danger Zone by Kenny Loggins when I try and swat the lil bastards!
  • In the midst of a banked turn, the flies can roll on their sides 90 degrees or more, almost flying upside down at times, said Florian Muijres

    "Do a barrel roll!"

    • Damn autocorrect. "McCloud", not McClure.

      Fly McClure? "Hi, I'm Fly McCulre. You may remember me from such vermin-borne illnesses as cholera and anthrax."

      Sigh.

  • Comment removed (Score:4, Interesting)

    by account_deleted ( 4530225 ) on Friday April 11, 2014 @03:14PM (#46728287)
    Comment removed based on user account deletion
  • When shit gets attacked it tries to get out of harms way. Thanks Slashdot. Now I know.

  • Who knew that the best thing to do when something dangerous was coming at you was to get out of its way as fast as possible...

    It's cool that they observed the fly behaviour...but it's not the most deeply insightful finding.

  • It will attract fighter jets.
  • "Too close for missiles, switching to guns!"

  • Good thing they didn't try to perform a split-S; that would have had Charlie all over them. Everyone knows it's the last thing you should do.
  • Do they scream out cliches like "I can't shake 'im" and "I got a bogey on my six!"? And, do they have ambiguously gay volleyball matches after a sweaty dogfight?

  • "... in less than one one-hundredth of a second, 50 times faster than we blink our eyes" 1/2 a second to blink?! or is the fly actually quicker than one-hundredth of a second?
    • by mbo42 ( 1161817 )
      ... if the image in the article is a real one, from the 7500 frames per second camera, it looks like the turn may be completed in less than one-thousandth of a second. That makes the 1/50th of a blink sound better.
    • "... in less than one one-hundredth of a second, 50 times faster than we blink our eyes" 1/2 a second to blink?!

      You are ignoring the "less than" part. And as far as I can find, typical human blink duration is roughly 400 milliseconds [cam.ac.uk]

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