158 
THE NATURAL HISTORY 
[LETT. 
because in such spots insects most abound. AVben a fly is taken, 
a smart snap from ber bill is beard, resembling tbe noise at tbe 
shutting of a watcb-case ; but tbe motion of tbe mandibles is too 
quick for tbe eye. 
Tbe swallow, probably tbe male bird, is tbe excuhitor to house- 
martins, and other little birds, announcing the approach of birds 
of prey. For as soon as a hawk appears, with a shrill alarming 
note he calls all the swallows and niartins about him ; who pur- 
sue in a body, and buffet and strike their enemy till they have 
driven him from the village, darting down from above on his 
back, and rising in a perpendicular line in perfect security. This 
bird will also sound the alarm and strike at cats when they climb 
on the roofs of houses, or otherwise approach the nests. Each 
species of hirundo drinks as it flies along, sipping tbe surface ol 
the water ; but the swallow alone, in general, washes on the wing, 
by dropping into a pool for many times together : i in very hot 
weather house-martins and bank-martins also dip and wash a 
little. 
Tbe swallow is a delicate songster, and in soft sunny weather 
sings both perching and flying ; on trees in a kind of concert, and 
on chimney-tops : it is also a bold flyer, ranging to distant downs 
and commons even in windy weather, which tbe other species 
seem much to dislike ; nay, even frequenting exposed sea-port 
towns and making little excursions over tbe salt water Horse- 
men on wide downs are often closely attended by a little party 
of swallows for miles togetber, which plays before and behind 
them, sweeping around, and collecting all the skulking insects 
that are roused by tbe trampling of the horses' feet : when the wind 
blows hard, without this expedient, they are often forced to settle 
to pick up their lurking prey. 
This species feeds much on little coleoptera, as well as on gnats 
and flies ; and often settles on dug ground, or paths, for gravels 
to grind and digest its food. Before they depart, for some weeks 
^ " Now suddenly he skims the glassy pool, 
Now quaintly dips, and with an arrow's speed 
Whisks by. I love to lie awake, and hear 
His morning song twittered to dawning day." 
