Okay, after a long journey we are back dealing with rodents, or should I say their demise.

Rodenticides are defined as any substance that is used to kill rats, mice, and other rodent pests. Warfarin, Bromodiolone and Difenacoum are some examples. These substances kill by preventing normal blood clotting and causing internal hemorrhaging. Fumigants such as sulfur dioxide, carbon monoxide, hydrogen cyanide, and methyl bromide are also effective rodenticides. In the past, Phosphorus paste, barium carbonate salt, and powders such as zinc phosphide, white arsenic, thallium sulfate, strychnine, strychnine sulfate, and calcium cyanide used to be mixed with bait and placed where rodents will find and eat them. All these poisons are toxic to other animals, and most cause death by disturbance of nervous-system functions. Red squill, a rodenticide derived from the bulbs of a lilylike subtropical plant, is slower-acting and less toxic to animals other than rodents because it is removed from the stomach by vomiting--a reflex that is absent in rodents.

So, as we can see from above a wide variety of materials are used as rodenticides. They pose a particular risk for accidental poisonings for several reasons:

  1. First, as agents designed to specifically kill mammals, often their toxicity is very similar for the target rodents and for humans. (Warfarin and other anticoagulant rodenticides were initially developed to overcome this problem by creating compounds that was highly toxic to rodents, particularly after repeated exposures, but much less toxic to humans).
  2. Secondly, since rodents share the same environment as humans and other mammals, the risk of accidental exposure is an integral part of the placement of baits for the rodents. TAKE NOTE PEST CONTROLLERS.....MAKE SURE BAIT IS PROTECTED. ALSO TAKE NOTE YOU DIY PEST CONTROLLERS.
  3. Thirdly, as rodents have developed resistance to Warfarin and others, there is a continuous need to develop new and potentially more toxic rodenticides. Thus we end up with 2nd and 3rd generation rodenticides which have increased the risk to humans.



© Stuart M Bennett 2012