In their wild state reindeer are great travelers, and as they are very strong, and excellent swimmers, they go immense distances, especially the reindeer of North America, who will cross the ice to Greenland in the early part of the year, and stay there till the end of October, when they come back to their old quarters. They are most sociable creatures, and are never happy unless they have three or four hundred companions, while herds of a thousand have sometimes been counted. The females and calves are always placed in front, and the big bucks bring up the rear, to see that nobody falls out of the ranks from weakness. Like many animals that live in the North, the color of the reindeer is different in winter from what it is in summer. Twice a year he changes his coat, and the immense thick covering which has been so comfortable all through the fierce cold, begins to fall in early spring and a short hair to take its place, so that by the time summer comes, he is nice and cool, and looks quite another creature from what he did in the winter. As the days shorten and grow frosty, the coat becomes longer and closer, and by the time the first snow falls the deer is quite prepared to meet it. Though reindeer prefer mountain sides when they can get them, their broad and wide-cleft hoofs are well adapted for the lowlands of the North of Europe and of America, which are a morass in summer and a snow-field in winter. Here are to be seen whole herds of them, either walking with a regular rapid step, or else going at a quick trot; but in either case always making a peculiar crackling noise with their feet. They have an acute sense of smell, and will detect a man at a distance of five or six hundred paces, and as their eyes are as good as their ears, the huntsman has much ado to get up to them. They are dainty in their food, choosing out only the most delicate of the alpine plants, and their skins cannot be as tough as they look, for they are very sensitive to the bites of mosquitoes, gnats, and particularly of midges. Reindeer are very cautious, as many hunters have found to their cost; but they are ready to be friendly with any cows or horses they may come across, and this must make the task of taming them a great deal easier. They have their regular hours for meals, too, and early in the mornings and late in the evenings may be seen going out for their breakfasts and suppers, which, in summer, consist, in the highlands, of the leaves and flowers of the snow ranunculus, reindeer sorrel, a favorite kind of grass, and, better than all, the young shoots of the dwarf birch. In the afternoons they lie down and rest, and choose for their place of repose a patch of snow, or a glacier if one is at hand.