Rats are known to spread life threatening diseases as well as for causing structural damage in the areas they infest. Rat poison is one of the several methods to control rodents.

Rat poisons are substances used to kill rats and other rodents. These come under the category of pest control chemicals. These can be gotten from most hardware stores, grocery stores, and even for free from recognized agencies in some areas. Rat poisons are not environmentally safe. They are not only poisonous to rats, but also toxic to animals and humans. There are several types of rodenticides available. They have a wide variety of active ingredients, but they require training and experience to apply safely and effectively.

Rat poisons can be broken down into three general groups. These are anticoagulants (warfarin, brodifacoum); bromethalin, a neurotoxin; and cholecalciferol-containing rodenticides. The anticoagulant rodenticides are the most common available in the market with trade names like warfarin, fumarin, diphacinone and bromadiolone. The mechanism of the anticoagulant rodenticides is to deplete vitamin K, which is required for normal blood clotting.

Bromethalin is a new non-anticoagulant designed to be fatal to rodents after a single dose. Bromethalin is a neurotoxin that directly affects the brain and cerebrospinal fluid. Clinical signs associated with ingestion of bromethalin appear about 10 hours post-ingestion and include severe muscle tremors, excitability, running fits, seizures and depression. This is a safer rodenticide for use where dogs are present.

The last category of rodenticide contains cholecalciferol or vitamin D. These rodenticides act by causing vitamin D toxicosis, raising serum calcium levels to dangerously high levels. Clinical signs arise within 18 to 36 hours after ingestion, and include depression, anorexia, increased urination and increased water intake. Heart conduction becomes slow and it may result in ventricular fibrillation and cardiac arrest.

If rat poisons are not properly applied, they can kill or otherwise endanger children, pets and other animals. So it is advisable to hire a licensed pesticide applicator well versed in rodent control to apply them.