When a buck exhibits flehming by raising/ pulling back upper lip he's checking urines scent for estrus phermones. I feel its part of why does loiter around certain scrapes at times.
If like dogs,humans and others ,estrus phemones in one could inspire(induce) cycle in others.
Due to reports of some older does coming into estrus before others i used to tie a strip of cloth out of deers normal reach above areas primary scrape with estrus scent. Early october. More study needed but scrape stayed active earlier and later in season with plenty of traffic the couple years i hunted it, all bucks during daylite from downwind.