The lethal ingredient in all of these rodent baits contains poison which stays in the food chain. The beneficial owl or raptor who eats the dead or dying rodent bait will also be ingesting the poison and eventually die, too. Owls and raptors are nature's 'rodenticide' so don't kill them off by using rodent baits. As an alternative, the electrified, self-contained rodent traps work really well.
