What is the most effective homemade poison for killing mice?

The most effective homemade poison for killing mice is not recommended by pest control professionals or safety experts because homemade poisons are unreliable, inhumane, and dangerous to children, pets, and wildlife, and there is no safe and effective homemade poison that is approved for use. Many internet recipes claim mixtures like plaster of Paris with flour, baking soda with sugar, or other food combinations will kill mice, but scientific evidence shows these methods have very low effectiveness, cause prolonged suffering rather than quick death, and often do not work at all because mice may not eat enough to be affected. Commercial rodenticides that are effective contain active ingredients like brodifacoum, bromadiolone, or cholecalciferol that are manufactured under strict regulations and must be used in tamper-resistant bait stations to prevent accidental poisoning of non-target animals. Homemade mixtures lack controlled dosing and can also be toxic to pets and humans if ingested. The most effective and humane methods that are recommended for homeowners are not poisons at all but quick-kill mechanical traps such as snap traps that break the neck within seconds and electronic traps that deliver a high-voltage shock, combined with exclusion by sealing holes with steel wool and caulk and sanitation by storing food in airtight containers. If you have a large infestation, contacting a licensed pest control professional who can use approved products safely is far more effective than trying homemade poisons.