What do houseflies really like?

[rjb]

Joseph C. Tallon wrote in message <379A21F1.87D29BFC at Netxn.com>...
>Rick form this we can conclude that these flies are not
>attracted to natural unoderized gas leaks like landfill methane
>collecting systems or natural leaks in the oil field business. Is anyone
aware
>of this being a problem ? I am personally aware
>of having a blu/greenbottle fly problem in a residence and discovering a
gas
>leak. They are somewhat rare in So. Cal as
>urban pests...Joseph Tallon
>
I am only guessing about the sulfur compounds being what attracts the flies.
Seems unlikely to me that they can detect CH4, C3H8 etc because these
molecules are not very reactive.  A sensor generally binds the molecule to a
receptor site and CH4 doesn't have a handle.
As to natural sources of gas, we had a natural gas ground leak in the
neighborhood where I grew up with an eternal burn-off flame. Whenever the
flame blew out, the neighborhood reeked.  That gas had odor.  Never knew
whether it was natural sulfur content or an additive.
I am guessing that if you release chemically pure methane or propane, the
bluebottles would not be interested.  If I had some flies available here,
I'd give it a try!
Rick