Still there was not sufficient till he hit on the idea of trapping the water-rats; and this is how he did it.
He took three small twigs and ran them into the bank of the brook at the mouth of the water-rat's hole and just beneath the surface of the stream.

These made a platform upon which the gin was placed--the pan, and indeed all the trap, just under the water, which prevented any scent.

Whether the rat came out of his hole and plunged to dive or started to swim, or whether he came swimming noiselessly round the bend and was about to enter the burrow, it made no difference; he was certain to pass over and throw the gin.

The instant the teeth struck him he gave a jump which lifted the trap off the twig platform, and it immediately sank in the deep water and soon drowned him; for the water-rat, though continually diving, can only stay a short time under water.

It proved a fatal contrivance, chiefly, as was supposed, because the gin, being just under the water, could not be smelt.