18 WILD NEIGHBORS CHAP. 
thoroughly the moment my back is turned; and 
when once the house was reoccupied after a long 
vacancy, we caught the squirrels peeping in at the 
windows and hopping gingerly to the sill of each 
open door, to make sure the matter was all right. 
It is most amusing to watch them on these tours 
of inspection. Two or three times a day each one 
makes the rounds of the premises, racing along 
the fences, and into one tree after another, as if 
to make certain that nothing had gone wrong. 
He will halt on the summit of each post, rear up, 
and look all about him; or, if his keen ears hear 
an unwonted sound, will drop down upon all-fours, 
ready to run, his tail held over his back like a 
silver-edged plume, twitching nervously and jerk- 
ing with each sharp utterance, as though it were 
connected with his vocal organs bya string. “All 
his movements,” said Thoreau, “imply a spectator.” 
The excessive inquisitiveness I have described 
often gets them into trouble, and is taken advan- 
tage of by their enemies. A wise serpent will coil 
himself at the foot of a tree where squirrels are 
playing, and will slowly wave his tail or display 
his red tongue, sure that the squirrels will see him. 
Doubtless they know him for what he is — a deadly 
enemy; but they cannot resist a nearer look at 
the curious object and that extraordinary motion. 
Whining, chr-r-r-ring, barking, they creep down 
the tree-trunk. The snake lies ready, his unwink- 
ing eyes fixed upon the excited little quadruped. 
