They dip and wash as they fly sometimes, like the house-martin and swallow.
The sand-martin, the house-martin's cousin, prefers the side of a cliff.
Undoubtedly they breed a second time, like the house-martin and swallow; and withdraw about Michaelmas.
Instead of the clay-built nest of the house-martin, this bird bores horizontal galleries in an escarpment.
The house-martin's nest is more elaborate than the swallow's.
The wall was perfectly flat, and they began to fasten mud against it as a house-martin would have done.