Ratsbane is a term used to refer to a substance meant to kill rats. Some of the synonyms for ratsbane include rat poison, rodenticide, raticide, vermin poison, mouse killer, and rat-killer. These terms are often used interchangeably to describe any substance or chemical that is used to control rat populations. Poisoning rodents is a common practice to eliminate them from homes, fields, and other areas. While these substances can be effective, they can also pose a risk to other animals and humans, which is why it is important to use them with caution and follow all safety guidelines and regulations.