probably the most potent attractant to fruit flies is the smell of fresh
baker yeast paste. acetic acid (10%) also works pretty well.
Dan Dopps wrote:
> I'm wandering what the most potent substance is that attracts flies. If
> one of you fine people would send me your expertise on this I would be
> grateful. I am looking for a chemical that will draw flies away from
> other compounds, such as sugar.