HIRUNDINIDS. 283 
amongst these flocks are almost always a few Mar- 
tins and Swallows. 
The Sand Martin differs considerably from the 
other two species in the manner of building and the 
locality in which it places its nest: this is always in 
a hole, which the birds usually excavate for them- 
selves: the place chosen for this excavation is gene- 
rally in some steep sand-bank or side of a cliff, where 
the nature of the soil allows them to work: about 
here they generally choose the perpendicular side of 
some quarry: the holes are made quite round, and 
are generally some two or three feet deep from the 
face of the bank or cliff: at the bottom of the hole 
a slight nest is made of hay and feathers; in places 
nearer the sea, sea-weed appears to be the article 
mostly made use of. In describing these holes all 
writers appear to agree in saying to young bird- 
nesters, “‘ Beware of fleas,” which abound in the 
nest itself, and even round the mouth of the hole in 
which it is placed. 
The food of the Sand Martin, like that of the 
Swallow and House Martin, consists almost entirely 
of insects, mostly flying ones. Yarrell, quoting 
White’s ‘Selborne,’ says the young are occasionally 
fed with dragonflies as long as themselves. I have 
never myself detected any of the Hirundinide taking 
dragonflies, or indeed anything much longer than a 
May-fly, which is a very favourite food with all of 
them. 
