250 FRIENDS WORTH KNOWING. 
ing chirrup being all its voice can accomplish; nor is it a 
handsome bird—simply sooty-brown above, white beneath, 
with a brown breast. To its grace of motion and charm- 
ing home-life we attribute that in it which attracts us. 
Although probably the least numerous of all the swal- 
lows, they do not seem so, because of the great compa- 
nies which are to be seen together wherever they are to be 
found at all; and because, leading a more sequestered life, 
they are not usually brought into direct comparison with 
house-martins and chimney-swifts. Eminently social in 
their habits, they congregrate not only at the time of mi- 
gration (then, indeed, least of all), and in the construction 
of their homes, but sometimes alight in great flocks on the 
reeds by the river-side and on the beach, where Sir William 
Jardine saw them, “partly resting and washing, and partly 
feeding on a small fly, which was very abundant.” Yet 
you will occasionally notice stray individuals associating 
with other swallows. 
The secret of the local distribution of the bank-swallows 
lies in the presence or absence of vertical exposures of soil 
suitable for them to penetrate for the burrows at the inner 
end of which the nest is placed. Firm sand, with no ad- 
mixture of pebbles, is preferred, and in such an exposure, 
be it sea-shore, river-bank, sand-pit, or railway-cutting, the 
