A little while after they heard a rat-a-tat at the garden door.
It was probably that, with some of the shells in the rack, that made all that rat-a-tat.
rat-a-tat, rat′-a-tat′, n. sound of repeated knocks, as of a drumstick.
The other guns quickly took up the rat-a-tat; the range was sent to the other five guns.
Then they heard a rat-a-tat, and the voice of their mother calling: 'Here!
1680s, echoic, originally of a cooper hammering tubs.