Male elephants have a vomeronasal organ by which they can detect when a female is in heat.

(http://www.nature.com/nsu/021001/021001-10.html)

The vomer and nasal bones are in the nose, according to CancerWEB (cancerweb.ncl.ac.uk). (What does the "WEB" in "CancerWEB" stand for? Anybody know?) Here's CancerWEB's definition of "vomeronasal organ":

vomeronasal organ

A specialised part of the olfactory system located anteriorly in the nasal cavity within the nasal septum. Chemosensitive cells of the vomeronasal organ project via the vomeronasal nerve to the accessory olfactory bulb. The primary function of this organ appears to be in sensing pheromones which regulate reproductive and other social behaviours. While the structure has been thought absent in higher primate adults, data now suggests it may be present in adult humans.

(12 Dec 1998)

(http://cancerweb.ncl.ac.uk/cgi-bin/omd?vomeronasal+organ)

If you understand all of that, you're doing better than me!

Tinman

Beats me why this is on "Cancer-web," since it's clearly not talking about nasal malignancies. However, I recall Desmond Morris doing a TV show last year demonstrating that humans do indeed exhibit an olfactory response to pheromones, thus suggesting that we aren't that much behind elephants in our ability to detect a female in heat. After all, it's NOT our brains telling us to get chummy!

The "WEB" part I think is just meant to be an indication that it's on the World Wide Web. Microsoft's Front Page HTML authoring software for some reason calls each site that the owner creates a "web". It may be that they got the idea from MS.