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How long does it take for rat poison to work

How Long Does It Take For Rat Poison To Work?

ne of the most common questions asked by homeowners and gardeners is how long does it take for rat poison to work?

Several factors contribute to the effectiveness of the rat poison. Rat poisons work through several different mechanisms. They depend on the ingredients used in the formulation. How fast the poison works is determined by the type of poison and how long it took the rat to accept the bait.

Under the right conditions, the poison starts killing rats within a day. To destroy all the population, give it a week or so.

Types of Rat Poison

Rat poison comes in a variety of formulations with small sachets being the most available ones. Rats prefer baits that are palatable – more like they love good things too. The sweeter the bait the longer the rats will feed and the faster they will react.

The three key ingredients used in the rat poison are, bromadioline, brodifacoum, or difenacoum. These three poisons affect the rats’ blood clotting response resulting in the death of the rodent a few hours or days after ingestion.

Types of Rat Poison

The types of rat poison include:

  • Bait blocks
  • Pasta Bait
  • Rodine rat and mouse killer bait
  • Rat killer bait

Find The Best Rat Poison That Won’t Harm Other Animals

How Long Does It Take for Rat Poison to Work?

After a rat ingests the poison it can take 2-3 days for it to die. Immediately a rat ingests poison, it stops feeding which reduces the risk of secondary poisoning. The effectiveness of the poison depends on some factors that include

  • Placing the poison in the correct places
  • Replacing spoiled poison right away
  • Removing all other food and water sources
  • Understanding the size of the rat
  • Increasing the effectiveness of rat poison

As we have seen, the effectiveness of the poison is what determines the time it takes for the rodents to die. Now that you know the different types of rat poison, it’s crucial to learn how to make the poison work faster and give better results.

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Here are several ways to do so:

  • Place baits roughly 30 feet apart and for heavier infestations 15 feet apart
  • Place the bait in the most affected areas
  • Inspect the bait frequently
  • Do not move the bait stations – rats respond positively to familiarity
  • Replenish more bait where it’s eaten as soon as possible
  • Continue baiting until all feeding activity stops
  • In wet conditions, use all-weather blocks
  • Use natural and familiar materials in the bait stations to encourage the rodents

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Factors Affecting Rat Poison Effectiveness

Is it a 1st or 2nd generation rat poison? When buying rat poison, you will likely come across 2 categories. The first generation kills rats slowly and they will need to feed on the poison multiple times. The second-generation poisons act fast and the rodent only needs to feed once for it to take effect. If you don’t remove dead rodents from the area fast, the other rodents can develop shyness of the bait. They start to associate the dead ones with the bait.

Rats may develop resistance to these poisons. Some of the 1st generation poisons have been used for a long time.  Over time, some rodent species have developed resistance to the effects of such poisons making them prone.

If the rodent has other sources of food. If there are other available food sources for the rodent, they will likely avoid the bait station. Rats are habitual feeders that are likely to avoid new feeding points if they can still access their accustomed feeding points. Before placing rat poison, clear out all other food sources. Be sure to get the poison to smell similar to the food they eat.

Placing the bait correctly. When placing the bait, set it correctly and securely. Keep your placement away from pets, babies, and bad weather conditions. Use a bait station or snap trap to know the effectiveness of the poison.


Now that you have a clear idea of how long it takes for rat poison to work, go ahead and use the poison with wisdom. If you still wonder if you should use first or second-generation ask yourself these questions:

  • Are your pets at risk of secondary poisoning?
  • Where are your rodents located?
  • How fast do you want them eliminated?
  • Are you going to remove their carcass after they die?
  • Do you have wildlife around your home that might ingest poison after eating the dead rodents and die too?

Whatever type you choose, remember to keep your children, pets, and environment safe from secondary poisoning.