Why are insects attracted to feces?

  1. I'm sure everyone's seen some dog crap lying on the street and a bunch of flies swarming around it, why does this happen? Are they after some left-over organic materials in the feces, or do they have any use for the inorganic waste products in their metabolism?
     
  2. jcsd
  3. marcus

    marcus 24,732
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    what a disgusting topic to raise
    however one can ask: what is doo-doo made of?
    I would guess that it contains the bodies of bacteria that flourish in
    the mammalian gut, and lots of organic fiber----cellulose

    some expert will no doubt descend, flapping his or her bat-like wings, and tell us what poop is really made of

    but let us suppose that I am right
    think about this: cellulose (which we cannot digest because we do not produce the enzyme cellulase to break it down into sugar) is a polymerized sugar. Therefore indigestible fiber is good food for any small beastie that can make the right enzyme.

    the Fabled Amerinds who once roamed the Great Plains used to build their campfires of Buffalo dung---which shows that, far from being inorganic, faeces are a rich source of calories---they burn when dry.

    Therefore, from a fly-maggot's point of view----hatched in the dung where his mother thoughtfully laid her eggs----it is a wholesome provender
     
  4. iansmith

    iansmith 1,430
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    Flies are attracted to warm moist place to lay eggs such as feces. Feces are also rich in decaying matter and the larvae will feed on the decaying matter. The bacteria in the feces are doing all the job.
     
  5. If flys loved cellulose, it would seem they'd all eat grass...

    Just because something burns, doesn't mean it's organic, or else methane would be considered organic, right?
     
  6. selfAdjoint

    selfAdjoint 8,147
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    What we mammals egest is too low in free energy for us to exploit for order building anymore, but not zero in free energy. Specialized creatures, both insects and bacteria, can extract some of the remaining free energy from our poop to generate their own order building operations.
     
  7. marcus

    marcus 24,732
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    methane is classified as an organic chemical

    My CRC Handbook of Chemistry and Physics has two sets of data on compounds, organic and inorganic, and methane is in the organic list.

    carbon compounds often are treated as organic and methane is CH4

    I wonder if fly larvae can actually feed on the bacteria that are thriving on the egested waste----yoghurt is made of the bodies of bacteria IIRC---perhaps the fly larvae think they are amidst a sort of yoghurt
     
  8. iansmith

    iansmith 1,430
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    Fly larvae probably feed on bacteria but I think is more acidental than anything else. On a side note, when you eat yoghurt there is 10^9 bacteria per gram.
    :biggrin:
     
  9. marcus

    marcus 24,732
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    you say :biggrin: but I say :tongue2: Yum Yum for yoghurt!

    I would rather eat a trillion bacteria than one kilo of cow
     
  10. Janitor

    Janitor 1,189
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    And after it sits around long enough-

    Theoretically there was a leash law in the neighborhood where I grew up. Despite said law, one undeniable hazard of playing front-yard tackle football (in addition to a knee injury that still can cause me problems to this day) was that a puff of white smoke would sometimes spray from underneath a tackled player. Somebody made the claim that it was white due to a dominant presence of the element phosphorus, but I never knew how valid this claim was.
     
  11. Alright, well bad example. But you get my point right, not everything that burns must be a hydrocarbon.
     
  12. marcus

    marcus 24,732
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    Of course I get your point! I am not correcting you I am talking with you. :smile:

    wood is an organic chemical----not a hydrocarbon but mostly cellulose which is a carbohydate not too different from sugar

    on the other hand pure hydrogen gas is not classified as organic (it has no carbon in it)

    neither does sodium metal and magnesium powder

    hydrogen and sodium and magnesium burn but they are not organic


    however most fuels are classified by chemists as organic

    to a chemist an organic chemical does not have to be one produced by a living organism..some meteorites contain organic compounds which were just in the organic crude the solar system condensed from---not made by life.

    professionals are endlessly inventive about screwing up language
    just some thoughts
     
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