Figure 3-3. Checking steel trap for correct setting.
The chain should be fastened securely to some object so that a rat cannot drag the trap
away. It may be nailed to the floor with a staple. To avoid losing rats or having them
get into holes, the staples should be placed on the chain as close to the trap as feasible.
Traps are placed in rat runs and inside or near the entrance to holes, generally with one
on both sides if rats can go in either direction. When placed along a wall, the axis of the
trap jaw must be parallel to the wall, with the nearest jaw almost touching it. The best
way to test a steel trap is to set it on a table and strike the trigger with a stick held
horizontally. If the stick hits the trap along the axis of the jaws, it will be caught, and the
trap will have been placed correctly. If the stick hits at right angles to the jaw axis, the
trap will spring, but the stick will be pushed up by the jaws and not caught. The same
thing will be true for a rat if his belly is over the trigger pan when the trap is sprung. The
essentials of setting steel traps are as follows:
(a) Set traps only in rat runs.
(b) Place the traps so that the axis of the jaw is in line with the direction
of rat travel, not at right angles.
(c) Move the spring to rest at 30 to 45 degree from the axis of the jaws.
(d) Place the trap so that end of the spring points out from the wall.
(e) Block all runways with boards, boxes, or other objects; place the
traps inside the blocked areas or in the most confined parts of the runs.
(f) Fasten the chain away from the rat runs and on or near the floor,
never over the run.
(g) Keep the chains from the adjacent traps far enough apart so that a
rat caught in one trap cannot spring the second.
(h) Fasten the chain so that the trap cannot be dragged into a hold or
wall crevice where the rat will be difficult to remove.