Why do horses show there teeth?

I gave a horse some polo's and it took them gently from my hand but after it had eaten them it pulled it head up and showed it's teeth, twice?

Why do horses show there teeth?
thats called fleman a horse does that when it is trying smell something or "taste" the smell of something new, when the horse intakes air that way the smell goes up to a place in its mouth and the horse is able to tell more about the scent. aka; what it is, hoe old it is, is it male or female. the horse probly smelled something knew, but i do know some horses who do that to show that their happy so she was probaly just happy.
Reply:They're smelling a female in heat. lol
Reply:Perhaps he was smiling at you for giving him a Polo?
Reply:When they see people, they just cant stop laughing!
Reply:Ah, you must be talking about rolling his lip!!??..... this is when they encounter a smell or taste they are trying to figure out.
Reply:Vampire horse?
Reply:it just wanted to show that when it eat the polo it teeth became brighter................
Reply:Its called "flehmen response " and the horse was sending scent to receptors on its palate.
Reply:The flehmen response, also called the flehmen position, flehmen reaction, flehming, or flehmening (from German flehmen, meaning to curl the upper lip), is a particular type of curling of the upper lip in ungulates, felids, and many other mammals, which facilitates the transfer of pheromones and other scents into the vomeronasal organ, also called the Jacobson's Organ. In the flehmen reaction, animals draw back their lips in a manner that makes them appear to be "grimacing". The action, which is adopted when examining scents left by other animals of the same species or prey, helps expose the vomeronasal organ and draws scent molecules back toward it. This behavior allows animals to detect scents, for example from urine, of other members of their species or clues to the presence of prey. Flehming allows the animals to determine several factors, including the presence or absence of estrus, the physiological state of the animal, and how long ago the animal passed by. This particular response is recognizable in stallions when smelling the urine of a mare in heat.
Reply:My horses do this too. It is a natural thing for them to do.

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