Ah, that makes sense.
But since you mentioned the ziploc bag, I was wondering if you saved them for a winter protein supplement for the chickens, or had some other use for them :)
As the previous poster said, remove any water they can breed in, and dump/refill animal water containers regularly.
Have you tried putting up fly strips or flypaper? I mean the sticky stuff that catches anything that lands on it. I'm sure it will not get them all, but it might get some. (But be...