340 USEFUL BIRDS. 
twilight Bats come out; that Nighthawks “sweep the sky” 
through the later hours of daylight; and that Whip-poor- 
wills and Swifts are sometimes a-wing throughout the night. 
So that whenever insects are flying there are birds to pursue 
them. These birds of tireless pinion cover a wide territory, 
and form a most potent check on insect life. 
SWIFTS. 
The spine-tail Swifts are Swallow-like birds that rarely if 
ever alight, except upon their nests or on the perpendicular 
sides of chimneys, rocks, hollow trees, or buildings. 
Chimney Swift. 
Chetura pelagica. 
Length. — About five and one-fourth inches. 
Adult.—Sooty-brown, paling to gray on throat and breast; tail rather short, 
spiny, and somewhat cigar-shaped, fan-shaped when spread; wings black- 
ish, long, narrow, and slightly curved. 
Nest. — Of sticks, glued to the wall of a chimney, hollow tree, or barn. 
Eggs. — White. 
Season. — April to September. 
The Chimney Swallow, as it is commonly called in the 
country, is one of the common sights of the summer twilight 
as it flies twittering above trees and house tops. When 
building its nest it breaks off twigs from the trees as it flies, 
and glues them to the chimney with its own saliva. It isa 
most expert insect catcher, and while hawking about for food 
for its young fills up its mouth and cheeks with ‘insects, 
carrying them much as a-chipmunk carries corn. It appears 
to be of a playful disposition. I saw a Swift one day in 
Concord apparently amusing itself by chasing Cedar Birds, 
that were fly-catching, over the river. When a Cedar Bird 
flew out over the water the Swift turned and chased it back 
into the trees again, often following so closely as to seem 
about to attempt to swallow the frightened and fleeing bird. 
Swifts catch flies, small beetles of various kinds, flying 
ants, bugs, grasshoppers, and other insects, and spiders. 
A notion exists that these birds introduce bedbugs into 
houses ; but so far as I know it bas never been proven that 
there is any parasite common to both human beings and 
birds, with perhaps a single exception, — the woodticks. 
