>
> I'm talking about the natural ones made from some sort of ground-up
> flowers. Are those OK?
Afaik natural pyrothroids aren't used anymore, because demand far
outweighs those naturally produced. (I forgot the name of the flower,
it is native to Africa, hereabouts its relatives are of ornamental use
only).
Nowadays synthethic pyrothroids used are derivates, optimized for
greater persistancy and toxicity. Even natural pyrothroids are toxic to
mammals, yes (though especially to insects/athropods). As with any
biocides, the survived critters are selected for resistancy.
ciao,
'gene