Poisons to Kill Rats
Rat infestations are not only troublesome, but dangerous. Rats carry many deadly diseases, including meningitis and typhus (See Resources 2). Poisoning rats is one way to deal with an infestation, and the first step is choosing the right poison. Understanding how they work will help you choose the best solution to your pest problem.
Anticoagulants
Anticoagulants kill rats by blocking the vitamin K cycle, making it impossible for the rodent's body to produce blood-clotting factors. Most anticoagulants are combined with poisons that damage the rat's capillaries, which leads to internal bleeding. Since the animal's body cannot produce blood-clotting agents, it slowly dies from internal bleeding. Warfarin, diphacinone, coumatetralyl, pindone, bromodialone, brodifacoum and flocoumafen are all listed as anticoagulants used to kill rats in a publication from the New Zealand Northland Regional Council. (See References 1)
Metal Phosphides
Metal phosphides kill rats relatively quickly, with death occurring between one and three days after ingesting the poison. The metal phosphide reacts with acid in the rat's digestive system to produce toxic phosphine gas, which quickly kills the animal by robbing it of oxygen. According to the State of Michigan Department of Natural Resources, zinc phosphide, the metal phosphide used in baits to poison rodents, is quite attractive and fatal to other wildlife, especially wild birds. (See References 2).
Calciferols
Certain strains of vitamin D can also work as rodenticides. While some vitamin D is beneficial to rodents, the large doses placed in the poison bait become toxic, causing increased levels of calcium in the body. This extra calcium dissolves and circulates in the blood, causing the blood vessels and some internal organs to calcify, leading to heart problems, internal bleeding and even kidney failure. Sometimes these calciferols are mixed with anticoagulants to increase the toxicity of a poison. Vitamin D3 (cholecalciferol) is a common calciferol used in rat poison. (See References 3)
Bromenthalin
Bromenthalin kills rats by depressing the central nervous system, causing a buildup of spinal fluid leading to paralysis. Death is quick, usually within one to three days, and the rodent usually dies with only one feeding. This poison works well for rodent populations that appear to be immune to anticoagulants. (See References 3)
Tags: internal bleeding, kill rats, metal phosphide, Poisons Kill, , produce blood-clotting, three days