Humans have lived with rats and mice for hundreds of years, and this entire period, we were trying to figure out a way to keep them out of our homes. One of the methods we came up with was the rodenticide, which is poison designed to kill rats. Rodenticides have evolved over the years, from heavy poisons such as arsenic or strychnine to chemicals that are less environmentally damaging, and safer to use around the home.
The first anticoagulant rodenticide was developed in the 1950s. This class of rodenticides works by disrupting normal blood clotting and coagulation processes so that the dosed animals suffer from uncontrolled bleeding. Today, we use a class of stronger anticoagulants called second-generation anticoagulants.
Other rodenticides that are not anticoagulants work in different ways. Bromethalin and cholecalciferol are some of the non-anticoagulant rodenticides currently in use.
First-generation anticoagulants must be consumed on multiple consecutive feedings in order for the rats to receive a lethal dose. This is because mammals can excrete first-generation compounds quickly, often within one week. Three first-generation rodenticides have been registered by the US EPA, including diphacinone, chlorophacinone and warfarin.
SGARs, or second-generation anticoagulant rodenticides, are significantly more potent than first-generation compounds. A single feed can deliver a lethal dose. The compounds brodifacoum and bromadiolone, as well as difethialone, are included in this class. SGARs can persist in bodily organs like the liver and are difficult to excrete, and they can be particularly harmful to birds and mammals. These rodenticides also pose the greatest secondary risk to animals that eat a poisoned rat.
The US EPA has registered non-anticoagulant rodenticides such as bromethalin and cholecalciferol, and they are also quite popular. These rodenticides have a variable potency. Rodent deaths can occur within hours to days after ingesting a lethal dose. They can also be divided into three chemical classes, which differ from each other as well as anticoagulants.
Bromethalin is a neurotoxicant and can poison the central nervous system, causing respiratory distress with a single dose. Although it is non-toxic in small quantities, cholecalciferol (the biologically active form of vitamin D) can be toxic in large quantities. However, prolonged low-level exposure can also make it dangerous. Consuming excessive amounts of cholecalciferol can lead to hypercalcemia (high blood calcium levels) and eventually kidney problems. Zinc phosphide releases a toxic phosphine gas when it interacts with stomach acid. It can cause rodent death within hours.
The rodenticide used during the control process will depend on your particular situation. If you would like to know more about rodenticides, or if you need help with the removal of a rat infestation, contact us today.