If he were walking past or around anything that he feared he kept his tail stretched at full length on the side of his body that was next the object--sometimes he held it many inches from himself. If something moved suddenly in front of him as he ran, his tail shot over him away ahead of his nose, as if projected there by his sudden stop. But it was the natural instinct of thrusting his tail at anything threatening him too suddenly for flight. Much of his play at times was a kind of mock fright in which he seemed to imagine himself pursued by all kinds of enemies--even myself--and the most familiar objects becoming terrible. Then the use he made of his tail was most exaggerated, having in it perhaps some of the elements of terrifying the enemy, as seen in the swelled rails of cats, the bristles of hogs, dogs, etc. One could not resist the impression that the tail was thrown out as a shield or a screen, but this did not always seem a satisfactory explanation, for it was certainly a very frail thing and very conspicuous. Besides, it would seem to furnish the enemy a good handle to catch hold of. The theory has been advanced that this last is the very purpose of this use of the tail; and from my study of this pet I became convinced that he thrust out his tail when suddenly surprised in the hope that _it_ might be taken and his body _left_. The skin on the tail of most rodents (of which the squirrel is one) slips easily from the bone, and leaves, to a grasping enemy, often a little bunch of "hide and hair." So Bunny offers this--feeling that he would rather leave his tail in jeopardy and go into life whole otherwise. The glass-snake (a lizard) in its efforts to escape, frequently _breaks off_ a portion of its tail, which the pursuing enemy may stop to capture while the body wriggles into safety. This, likewise, is doubtless one of the reasons why the squirrel insists upon the tail's being always curled up over his back while he is absorbed in eating. It is not always merely a beautiful pose. As he thus sits in the trees his greatest enemies are the various large birds of prey which may dart down on him from above. Now, this mass of tail that is above him is apt to mislead the aim of the enemy, and, like the pioneer's cap thrust around the tree, is intended to draw the fire into a harmless medium. There can be no doubt that a squirrel uses his tail to steer him in a leap, much as the tail steers the boy's common kite. Perhaps, also, it acts slightly as a balance, but in this respect its greatest use must lie in its "up and down" rudder effect--or rather parachute-like effect--as he makes those tremendous leaps from a tall treetop to the earth. Here it comes well into play in lessening the shock of alighting, an emergency enabling him to escape some enemies--as a weasel or mink, perhaps--which may chase him around in the trees.