Intraspecific signals priming pheromones

As the males of most animals search for the females, these odoriferous glands probably serve to excite or charm the female, rather than to guide her to the spot where the male may be found. 

CHARLES DARWIN 1896) Dcsccnt ofMun and Selection inReUtion to Scx, p. 352 

In the rat, olfactory communication results in the synchronization of estrous cycles within a female social group the majority of females are likely to be at the same phase of their estrous cycles on the same day. 

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