The Food of Birds 149 
rows; warblers and vireos scan every twig and leaf; 
flycatchers, like the cat family, lie in watch and spring 
after their prey, only in the air instead of on the ground, 
feeding more particularly on low-flying insects; while 
swifts, swallows, and martins glean their harvest from the 
diurnal hosts of high-flying winged creatures. Many 
Fic, 115.—Crab. 
times when we think hummingbirds are taking dainty 
sips of nectar from the flowers, they are in reality pick- 
ing minute spiders and flies from the deep cups of the co- 
rollas. When night falls, the insects which have chosen 
that time as the safer to carry on their business of life 
are pounced upon by nocturnal feathered beings—the 
cavernous mouths of the whippoorwills engulf them as 
they rise from their hiding-places, and the bristles of 
