FEBRUARY. 71 



the borer in the trees, by the little nibbling sounds of the 

 grub, which their acute sense of hearing enables them to 

 perceive. Having ascertained the spot from which the 

 scratching proceeds, they hammer at it with their beaks, un- 

 til they have drilled into the very lurking place of the grub. 

 It is hardly possible to over-estimate the services done by 

 these birds in their ceaseless operations among the trees. 



This habit of perforating the bark of trees in quest of their 

 prey has given rise to the notion that they do so for the pur- 

 pose of tasting the sap. Hence the name of "sap-suckers," 

 which is frequently applied to them. The small speckled 

 woodpecker, so common in Massachusetts, often carries his 

 little perforations entirely round the trunks and branches of 

 the trees, in regular circles, so near to each other, that accord- 

 ing to Wilson, eight or ten of them may be covered by a dol- 

 lar. The trees have never been known to be injured by these 

 perforations, which are undoubtedly the surest means they 

 can use for dislodging their prey. 



I have as yet only alluded to the insects that come abroad 

 during the night. As a check upon their excessive multipli- 

 cation, as I have already remarked, nature has created certain 

 species of nocturnal birds, which, like swallows, catch their 

 food chiefly on the wing. These birds are of the whippoor- 

 will tribe, including in this country only two species, the 

 whippoorwill and the nighthawk. These two species have 

 similar habits, except that the latter does not confine itself to 

 the woods, but comes abroad after sunset and performs its 

 aerial gambols over our farms and villages. Each of these 

 species of birds are employed like the bat, in consuming the 

 nocturnal insects. Of the latter there are numerous tribes, 

 including a great variety of moths, gnats, beetles and others 

 equally destructive to vegetation, or annoying to our com- 

 fort. 



The birds of the whippoorwill tribe, though large, are ena- 

 bled to seize the small nocturnal insects, such as the gnats, 

 by having a wide mouth, which they keep open while mov- 

 ing through the swarm, shutting it when it is replenished 

 with insects. The nighthawk, when flying thus with its 



