The prairie-dogs like sandy or gravelly soil for their homes, and in making them they do a lot of ploughing. And besides they supply this same soil with a great deal of humus--the grass that they use for bedding. They're very particular about changing their beds every day; always clearing out the old bedding and putting in new. They do this along about sundown. You can see them do it right in New York City, for there is a flourishing colony of them at the zoo. [Illustration: THIS MUST BE A PLEASANT DAY In nice weather the Prairie Dog's front door stands wide open like this, but before a rain he stuffs it tight with grass because, when it _does_ rain in the arid regions where he lives, it comes down in bucketfuls!] Mr. Prairie-Dog is about a foot long and as fat as butter. The reason he's called a dog isn't because he is a dog or even looks like one, but because he has a sharp little bark like a very much excited puppy. He thinks he sees something suspicious: "Yap! Yap!" Or he spies a neighbor down the street: "Yap! Yap! Hello, neighbor! Looks like another fine day, doesn't it?" "Yap! Yap!" says neighbor. (This "yap" passes for "yes," no doubt--although it isn't quite the way Mr. Webster would say it, perhaps.) Then maybe a neighbor from away over on the avenue, that he hasn't seen for some time, comes calling--as they're always doing, these neighborly little chaps. Then it's: "Yap! Yap! Yap! Yap! Why, how _are_ you? And what have you been doing? And how are the little folks?" And so it goes, all day long. The prairie-dog's native home is on our Western plains, but he has a cousin away off in South America--although he may never have heard of him--called the viscacha. The viscachas live on the great grassy plains of the La Plata in colonies of twenty or more, in villages of deep-chambered burrows with large pit-like entrances grouped close together; so close, in fact, that the whole village makes one large irregular mound, thirty to forty feet in diameter and two to three feet high. These villages being on the level prairie, the viscachas are careful to build them high enough so that floods will not reach them. They make a clear space all around the town. In doing this these little people seem to have two purposes: (1) To make it more difficult for enemies to slip up on them unnoticed, and (2) to furnish a kind of athletic field for the community; for it is in these open spaces that they have their foot-races, wrestling matches, and the like. If you ever happen down their way, the first thing that will strike you is the enormous size of the entrances to the central burrows. You'd think somebody as big as a bear lived in them. The entrance is four to six feet across and deep enough for a tall man to stand in up to the waist.