I think this explanation is likely correct, but some of the reasoning seems irrelevant (or only somewhat relevant?). If cats were attracted to some other component of the smell of (specifically) these plants, and engaged in the same behaviors, it would produce the same benefit. The fact that the chemical they are detecting actually <i>is</i> the active ingredient seems... almost coincidental?<p>Unless cats, over their evolution, encountered a larger range of iridiod producing plants?