In rambling the woods I have often heard these squirrels barking and "chickareeing" with wild hilarity, apparently from the pure joy of living. Then again they proclaimed my distant approach, or presence, with unnecessary vigor. The energetic protest they make against the trespasser in their woods, is often, if not always, taken by big game as a warning. Generally on hearing this the game will be all alert for some seconds, and occasionally will move off to a more commanding position. Sometimes birds will stop and listen when this tree-top sentinel shouts warnings which have often saved big game from being shot. Most hunters hate this squirrel. There are brief periods in winter when these squirrels disappear for days at a time. The kind of weather does not appear to be a determining factor in this. During this disappearance they probably take a hibernating sleep; anyway, I have in a few cases seen them so soundly asleep that the fall and fracture of their tree did not awaken them. They sometimes live, temporarily at least, in holes in the ground, but the home is usually in a hollow limb or a cavern in a tree-trunk well toward the top of the tree. Commonly four young ones are brought forth at a birth. Cunning, happy midgets they are when first beginning their acquaintance with the wooded world, and taking sun baths on a high limb of their house tree. Just how long they live no one appears to know. As pets they have been kept for ten years. A pair lived near my cabin for eight years, then disappeared. Whether they migrated or met a violent death, I never knew. There was another pair in the grove that I kept track of through eleven years. This grove was a wedge-shaped one of about ten acres that stood between two brooks. With but few exceptions, the trees were lodge-pole pine. My acquaintance with the pair began one day in early autumn. Both set up such a wild chatter as I approached the grove that I first thought that something was attacking them. Seated upon a log close to the tree which they occupied, I watched them for three or four hours. They in turn watched me. Failing to dislodge me by vehement denunciation, they quieted down and eyed me with intense curiosity. I sat perfectly still. Evidently they were greatly puzzled and unable to make out what I was and what of all things on earth it could be that I wanted. With beady eyes they stared at me from a number of positions in several trees. Occasionally in the midst of this silent, eager eying one would break out in a half-repressed and drawling bark that was unconsciously, nervously repeated at brief intervals.