They keep this up on sunshiny days all through July and along into early August. Then the serious business of life begins. They sober down, these chipmunk children--they were only born last May--and learn to make homes for themselves. You never would think the way they love the sunshine that the homes of all the chipmunks are under the ground, and as dark as can be. But they are. You notice the chipmunks have rather large feet, considering what dainty little creatures they are. These feet, like the feet of the mole, are for digging. The chipmunk digs deep under the roots of trees and stone walls, if there happens to be either handy by, but, so far as I've seen, he's quite contented to make his burrows in the open meadows. The round nest at the end of the burrow is lined with fine grass. It has two entrances, one right opposite the other, like front and back doors. Sometimes there are as many as three doors; four, maybe, in case of a chipmunk of a particularly nervous disposition. All chipmunks are easily frightened and dive into their holes, quick as a wink, when there's any danger; and often when there's really nothing to be scared at at all. WHEN THOSE EXTRA DOORS COME HANDY But you can't blame them. There are times when it's no fun being a chipmunk, I tell you. The hawks get after you, and the minks and the foxes and the weasels. Those extra doors into the nest are very useful places to dodge into when you're outside and a savage old hawk swoops down on you, or a fox makes a jump at you. And they're just as handy--these extra doors--to run _out_ of when a mink or a weasel follows you in. They'll do that, if you're a chipmunk; chase you right into your own house! When a pair of grown-up chipmunks start housekeeping for themselves--that is to say when they are about ten weeks old--they first dig a little tunnel, almost straight down for several feet. Then they make a hall that runs along horizontally--like anybody's hall--for a few yards. Then, supposing you're Mr. or Mrs. Chipmunk in your new place, after it's all done--you go up a slant--a flight of stairs, you might say, although, of course, there aren't any stairs--and there you are in the family bedroom, the nest. Not long after the chipmunks stop their outdoor games in the Fall you might think it was because they had the mumps; they go around with their faces all swelled out in such a funny way. The reason is they have their cheeks full of nuts and seeds that they are storing for the Winter. They don't put these stores in the nest--for then where would they sleep, the nest is so small--but in special cellars that they build near the nest, with connecting passages. These cellars, like the nests, are well below frost-line, so that Jack can't get the nuts or nip the noses of the chipmunks while they are asleep. [Illustration: PICTURESQUE HOME OF A CONNECTICUT WOODCHUCK