Rat and Mouse Killer Plus by Deadfast Unwanted rodents can be killed with a single dosage of grain. It is a very appetizing grain bait that is ready to use and designed to compete with food sources, particularly cereals. Additionally, it contains Bitrex®, a bitter additive that guards against accidental intake by kids and animals. It is the sort of bait that is most similar to a mouse or rat's diet and contains an advanced active component.