This week, parents with young children are likely to be quizzed about reindeer, so here are some reindeer facts:

The first point to make is that reindeer are real. In North America, those living in the wild are called "caribou." In Eurasia, they're "reindeer." All populations, however, belong to a single species, Rangifer tarandus. They are large members of the deer family. Male reindeer weigh 275 to 600 pounds; females 200 to 300 pounds.

In North America caribou occur almost exclusively in Canada and Alaska. European reindeer roam northern Scandinavia and Russia. Much of the European herd, though, is domesticated, an important source of meat and hide to natives.

Unlike other members of the deer family, both sexes of caribou grow antlers. Racks are much larger than those of white-tailed deer. Bucks shed their antlers shortly after breeding. Does retain theirs until spring calving. This gives pregnant females a formidable weapon to protect themselves from wolves and grizzly bears. Females also use their antlers as shovels to scrape away snow to find food on the frozen tundra.

Caribou inhabit both the northern boreal forest and the tundra. Woodland caribou wander throughout the year in search of food, but they cover relatively small distances. Barren-ground caribou, on the other hand, are noted for long-distance migrations across the tundra. Some herds travel as far as 3,000 miles each year.

Caribou move in tremendous herds. One account from 1792 described a herd as, "180 miles in length, by 100 yards in breadth." That herd was estimated to consist of more than 3.5 million caribou. Today herds numbering tens of thousands are more typical.

For protection against the cold, caribou wear a coat of thick fur. Their fine, dense underfur is covered by a layer of coarse, hollow guard hairs. These outer hollow hairs insulate the body and improve the caribou's buoyancy. Consequently, caribou are excellent swimmers; they must be to cross the many rivers that cross their migratory routes.

Finally, when the part about reindeer flight comes up, you're on your own.