Rodenticide
Rodenticides are a category of pest control chemicals intended to kill rodents.
Single feed baits are chemicals sufficiently dangerous that the first dose is sufficient to kill.
Rodents are difficult to kill with poisons because their feeding habits reflect their place as scavengers. They will eat a small bit of something and wait, and if they don't get sick, they continue. An effective rodenticide must be tasteless and odorless in lethal concentrations, and have a delayed effect.
Read more about Rodenticide: List of Rat Eradications