What unique idea does Danny come up with to help his father take his revenge in Chapter Eleven?

Danny suggests that his father poach the pheasants by using sleeping pills sewn into raisins. Danny’s father is exalted about the idea, realizing that if they give the pheasants the raisins at dusk, by the time they go to roost for the night, the sleeping pills will kick in and they will fall from their roosts in the trees.