You know Dasher and Dancer, and Prancer and Vixen, Comet and Cupid, and Donner and Blitzen. And you may recall, that most famous reindeer of all -- Rudolph, the red-nosed reindeer.
But what do you really know about reindeer? Is your knowledge limited to song lyrics, or are you so well-versed in reindeer realities that you could apply for work at the North Pole stables?
If you're not a reindeer wrangler, there may be a few things you can learn about Santa's sleigh-pullers.
* Rudolph, the red-nosed reindeer ... may be a cow
Reindeer are not referred to as bucks and does, but bulls and cows, and it's possible that the reindeer who pull Santa's sleigh are cows.
"It takes eight ladies to keep that fat, silly man from getting lost," jokes Matt Shadle, who keeps a small herd of reindeer at his Christmas tree lot in Sandy.
Reindeer (and the closely related caribou) are the only deer species in which both the males and females grow long antlers, he said. In pictures and movies, Santa's reindeer almost always have antlers during their holiday deliveries, so they must be female.
"Males lose their antlers, usually, before Christmas," explained Troy Hirschi, who looks after a few reindeer as properties manager at This Is the Place Heritage Park in Salt Lake City. "Females actually keep them a little longer."
There is one other possibility: "If Santa had his reindeer 'fixed,' they could still be male," said Fay Cutler, of West Corinne Reindeer Station, explaining that steers keep their antlers a little longer than bulls.
* They really do click, click, click
In the famous Christmas song "Up on the Housetop," there's a "click, click, click" sound when Santa's on the roof. That sound could be the reindeer.
"They actually click," said Todd Brown, of Wellsville, who shows live reindeer at Christmas events. The clicking isn't the sound of hard hooves striking a wooden roof.
"They have a special tendon that develops in the heel at about 1 year of age," said Brown. When that tendon slides over bone, it makes a clicking sound.
Hirschi says the sound is about as loud as a person snapping his fingers.
"The theory is that it's an evolutionary thing, to allow the herd to hear each other as they walk through a blizzard," said Brown.
* Let it snow, 'cuz they can control their blood flow
Reindeer are built to stay warm in a snowy climate, with two kinds of hair on their bodies and the ability to restrict blood circulation to extremities.
The hair next to the skin is fine and woolly, according to Fay Cutler, of the West Corinne Reindeer Station. The outer layer is guard hair.
"Guard hair is long, slender and hollow," she said.
That combination is the perfect way for reindeer to beat the cold.
"If they lie down on the snow, the snow underneath would not melt at all," said Wellsville's Brown. "The coat holds in all of their body heat and doesn't allow body heat to escape."
As an added bonus, the hollow hair helps reindeer float. They can't fly -- without magic, of course -- but they're great swimmers.
Reindeer also handle the cold by cutting off their circulation. If the temperature hits about 30 degrees below zero Fahrenheit, blood vessels in the legs constrict.
"Most of the blood flow stays in the body area to keep them warm," said Hirschi.
The temperature in the lower legs can go down to about 33 degrees Fahrenheit, according to the Reindeer Health Aide Manual from the University of Alaska Fairbanks Cooperative Extension Service, while the reindeer's abdomen stays a normal 101.5 degrees.
It's actually much harder for them in warm weather.
"Reindeer don't have sweat glands," said Brown. "They pant like a dog if they get hot."
* All they want for Christmas is their upper teeth
Reindeer can be picky eaters, but who can blame them -- they don't have top front teeth and they have a four-chambered stomach like cattle.
"Reindeer can eat any vegetation on the tundra, and they have an amazing sense of smell to detect food beneath snow," said Shadle.
In the wild, they eat a variety of plants during the summer. In winter they mostly eat lichen, also called "reindeer moss," which is high in carbohydrates to give reindeer energy, according to the Reindeer Health Aide Manual.
In Utah, reindeer ranchers often feed them deer pellets.
"They like the leaves out of alfalfa, but they don't eat the stems, so my poor horse gets the stems when they're through," said Cutler. "You can't change their diet on them, or you'll make them sick. ... Even if you're changing from one brand of deer pellet to another brand, you need to graduate it."
For dessert, Cutler says, her reindeer like dandelions and grated apples. Hirschi says one reindeer at This Is The Place has special preferences.
"With Bambi, her favorite thing she loves eating is Cracklin' Oat Bran cereal," he said. "You can put it in your lips, and she'll take it out of your lips and give you little kisses."
* Get out of the way, Grandma
Grandma could get run over by a reindeer -- they can run up to 50 miles per hour, according to the San Diego Zoo website, www.sandiegozoo.org.
The animals were domesticated between 3,000 and 7,000 years ago, the zoo says, in arctic regions of Norway, Sweden, Finland and Russia.
"Reindeer were introduced to North America as a project to help Eskimos because whaling was going down the tubes," said Cutler. "They were a herd animal, used for meat, for milk and for their fur, and they could ride them or use them to pull."
Although they can attack with antlers and front feet, they're usually easy to tame.
"Two of mine are halter-broke," Cutler said.
Want to learn more? Check out "Reindeer Roundup: A K-12 Educator's Guide to Reindeer in Alaska," at www.uaf.edu/files/snras/MP_04_07.pdf.