The delay between a rat consuming poisoned bait and dying can vary according to several factors. There are a couple of different rat poisons in common use in the UK, and each is available in different concentrations. The most potent formulations of rat poison are restricted to pest control professionals; they are considerably more powerful than the poisons available off the shelf to consumers.
Rat poisons are collectively known as rodenticides, and the poisons currently in use can be divided into first and second-generation poisons. Both first and second-generation rat poisons work in the same way; they are anticoagulants, meaning they interfere with the rat’s blood’s ability to clot. As the rat’s blood thins, it eventually leads to internal bleeding, which ultimately causes the rat to die.
Second-generation rodenticides work quicker than first-generation poisons. First-generation rat poisons require multiple feeding sessions and doses before they take effect, meaning that it usually takes around a week for rats to die. On the other hand, second-generation poisons are effective after a single administration. However, they still take around three days to kill a poisoned rat.
As well as their faster efficacy, second-generation poisons also have the advantage of higher toxicity, which reduces the chances of secondary poisoning. Secondary poisoning occurs when one animal eats another animal that died due to poisoning. If there is enough poison in the dead animal, an animal that eats it can also ingest a lethal dose. With first-generation poisons, a family cat or dog could eat a dead mouse that’s been poisoned and end up poisoned themselves. With second-generation poisons, you don’t have to worry about this eventuality. Fresh rat poison is more potent than old poison, especially after being exposed to air while in storage. You should replace bait frequently to ensure it’s as fresh and effective as possible.