This section is from the book "The Balance Of Nature And Modern Conditions Of Cultivation", by George Abbey. Also available from Amazon: The Balance Of Nature And Modern Conditions Of Cultivation.
The Barrel Trap (Fig. 85 H) consists of an ordinary cask with one end out, and a lid with four falls (z). The falls are not less than 6 in. long and 3 in. wide, each working on two pivots (b), and this end of the fall weighted with lead (c) so as to recover its position. Outdoors, sink the barrel in the ground, indoors, place on the floor and set a bundle of straw against the barrel in a slanting direction, covering with an old sack so as to facilitate access to the lid. Place the cover on the barrel, securing the falls by means of a button under each (d). Affix a couple of strong red herrings on the centre of the lid (a), and scatter some oatmeal flavoured with oil of aniseed about the bait. Entice the rats in that way for a few nights, not being sparing of bait. After the rats take the bait freely and become accustomed to the lid, place in the barrel 9 to 12 in. of water (I f), turn each button (e) from under the falls, affix the lid by a few nails, bait as before, and the vermin setting foot on the falls drop into the barrel.
Remove the drowned rats daily, and after coating with quicklime bury them in the manure heap.