Tips for Safe Use of Mice Poison


Mice, mice, mice… The bane of many households, nice though they are (to some – frightening to others), they can be a real nuisance, especially when you have not one, but many ‘little ones’ as unwanted guests on your home.

This seems to happen especially where the building you live in is old; brick buildings, in particular, are far more prone than others to being inhabited by these little rodents; for example in an old city such as London, a brick metropolis of fifteen million people, the locals keep saying that, “You are never more than a meter away from a mouse.”

Other conditions that lead to the proliferation of mice are also important:

  • The local climate, for one, is an important factor; if it is mild, especially in winter, mice breed in this season too, while if they are cold they will tend to die off in this season.
  • Food left out of cupboards, with its smell, can attract mice from a distance especially (against popular belief, which wants us to fall for the fallacy that mice love cheese above all foods) cereals like wheat, oat and rye and their products (like flour, cakes, bread etc.). Thus, the first thing to do if you do not like mice at home is to avoid leaving food around. Yet another thing mice find irresistible is sugar! They go mad for it in all its forms, so, keep it away from them…

The most annoying thing about mice is not that they are mainly nocturnal (they will start being heard at about sunset) and that they may disturb you by squeaking at night, but that they leave droppings all over the place, especially in the kitchen or paltry where you cook or keep your food.

It is the droppings that are unpleasant and can bring disease, rather than the animals themselves, unlike rats, which are a different species of rodents.

Thus, if you have this problem to solve, the first thing to do is, if you have a ‘green’ conscience and you care about not hurting fellow inhabitants of this planet, is to try alternatives to poison, for example:

  • Keeping a cat is by far the easiest and safest way to get rid of mice.
  • Using peppermint essential oil is a lesser known remedy to this problem; it is a mouse repellent. All you need to do is sprinkle a few drops of the oil on cotton buds then place them around the house, especially where you see that they walk.
  • Mice repellent sounds, which are ultrasounds and noises with a very high pitch, also known as ‘zappers’, now available with apps. This method should be used as soon as possible, as it may fend off the little rodents for some time but they may come back. It also only works if you keep food out of their reach. Finally, some people who have used this say that they have had a headache as a result.

If all fails, maybe the only alternative is poison. However, using rat poison (maybe a misnomer, as it is primarily used for their cousins), is not as easy as it seems.

To start with, you need to make sure that you know which poison to use; second, you need to take precaution; third, just placing poison around the house is not enough, as we will see; finally, you will still need to keep food locked away and out of their reach.

Moreover, do not expect your house to be mouse-free within a day of placing the poison; it can take up to two weeks to stop seeing them walking around your home or hearing them squeaking when you go to bed.

Many people choose to use a professional and call pest control to do the job, but if you decide otherwise or you cannot, the following are the ten best tips to use poison to kill mice.

Choose the Fastest Poison

In my own experience with mouse poison, I recall being quite upset when I discovered that there is no product that kills these little rodents immediately. This means that they suffer a lot before they die.

You will hear mice squeaking in pain as they are slowly being poisoned. Pest control operators use poison which acts faster than the chemicals available on the market. To be allowed to use them, one needs to have a license in most countries.

Such poisons do not need to be ingested by the animals; all they have to do is get into direct contact with them and they absorb it through the skin. These are much more powerful than those you can usually buy over the counter in most places.

However, people do sometimes (in countries where regulation is lacking, or through friends, etc.) get into possession of this type of product.

If you do, make sure that you use protective gloves when using them and that you only place the sachets (these poisons are usually on the market in sachets with a humid paste inside) where children cannot absolutely reach!

Just touching them is dangerous, and if a child – or even an adult – then touches his or her mouth or eyes with the poisoned hand, the consequences can be really awful. If it happens, go straight to the emergency.

Even among the products freely available on the market, there is a huge range; some kill mice over a fairly long period of time (meaning that they start functioning only after a long period, up to two weeks as we have said); this is because the mice need to eat a large quantity of poison before it has a visible effect. In this period, they start feeling sick, but slowly; thus their pain is prolonged over time.

Usually, fastest-acting poisons are more expensive than slower ones; the price range may vary significantly, with some costing up to about 50% more than the average ones. You may think that this is not worthwhile, but instead, buying more expensive chemicals has some clear advantages:

  • To start with, they kill mice faster, as we have said, which means that they suffer less and you solve the problem faster.
  • Secondly, they are more reliable and safe because, as we will see later, not all poisons are always effective.
  • Finally, buying cheaper ones may be a false economy because you may end up having to buy it again and again, as the first dose may not be enough.

How Mice Poison Works?

As it is a dangerous product, it is always safer to know how it works. Most poisons are blood anticoagulants; this means that it starts working only when the chemical gets into the bloodstream (in itself, slower than if it affected the nervous system, as does cyanide, for example).

The little animals, then, start having internal bleeding till they die. As you can see, it is not a pleasant way to go…

However, it is also important to know how it works as it may happen that you or a member of your family or household (and that includes your pests) ingest some poison by mistake. Thus, if you have one of the following symptoms, consult a doctor immediately:

  • Nausea
  • Vomiting
  • Diarrhoea
  • Blood streaked diarrhoea
  • Stomach cramps
  • Dizziness
  • Hair loss
  • Seizures
  • Lethargy
  • Nasal problems

The symptoms may appear suddenly or even over many days.

Check if the Poison is Working

The reasons why you should check that the poison is working are as follows:

  • You need to make sure that it is the right one for your mice, or you may have to use another one.
  • You can keep track of the progress of your disinfestation.

How do you check? There are some signs you need to look out for:

  • Reduced quantity of droppings
  • Reduced appetite (the mice eat less poison)
  • Reduced activity (less noise at night etc.)
  • Mice squeaking in pain
  • Never touch the poison with your hands when checking!

If none of these signs are present after a few days, consider changing poison.

Where to Place the Poison?

People handling rat poison need to do it very carefully; as we have already said, it is a very noxious substance.

To start with, there are two criteria that you need to follow in order to position it both safely and efficiently. Many people who choose the “do it yourself” option to eliminate these rodents from their homes often make mistakes, which ends up causing their work to be both ineffective and dangerous.

Thus, if you wish to avoid these risks, you should keep in mind the following instructions: Place it out of the reach of children and pets.

  • Place it out of the reach of children and pets.
  • Place it where the mice walk regularly. You can find these spots by checking where the droppings are. Usually, mice tend to walk next to walls rather than in the middle of rooms as they do not feel safe on open ground (because in nature they have many predators). Thus, the most common places to put the poison are under cupboards, behind the fridge and in small spaces between items of furniture etc.
  • Although mice will tend to walk on the floor in houses and flats, they can climb very well, especially if attracted by the smell of food; therefore, make sure you check for droppings on top of cupboards as well.

How to Place Rat Poison?

It is important that when you put the poison around your home, you also know how to put it correctly. To start with you should never put the poison directly on the floor.

This is paramount as if you do so, you risk having it spread all over the place by the little feet of the rodents; this may constitute a serious health hazard, so be particularly careful.

You should, instead, place it on little plastic trays. Some products come with their own plastic trays; others do not, thus you will need to purchase them separately.

If you wish, you can make your own, or adapt other containers to the purpose; plastic plates can double up as poison trays for example. However, make sure that once you use them to hold the rat poison you never use them for any other purpose.

Do not even consider washing them and recycling them; better safe than sorry.

Bait or no bait?

Products can be divided into two categories; poisoned bait and poison with no bait.

In the first case, you will see that in the box or tub you buy you have grain or small seeds (as we have said, mice love cereals above all) of a strange, often quite striking color (blue and red are very popular).

This is not because that is the color of the poison; instead, it is a safety precaution to avoid mixing the bait with the food you eat by mistake.


In case the poison comes with no bait, you will have to provide your own. As you should know by now, do not go for cheese; not only will it stink after a few days, but the mice will keep heading for the bread bin instead…

So, your favorite choice should be cereals, small seeds, even bread (crumbs), and sugared water. Place it next to or on the poison itself and wait…

Check if Mice are Eating

As we have said, and we will talk about it more specifically in the next section, not all poisons work for all mice; moreover, you need to make sure that the little rodents are actually eating the bait.

Do not just place the bait in the trays and forget about it. Instead, on a daily basis, check that the mice have eaten it. You can see this by looking at the quantity of bait, the presence of husks, etc.

mice are eating

You may need to replace it very regularly. Do remember that their appetite will drop significantly once the poison has started working.

If they do not eat, they may have another source of food; thus, check again if they have access to cupboards, etc.

Making sure they are eating the bait and poison also means not leaving the noxious substance on the floor of your home for too long, as it may disperse in the environment.

Mice Becoming Immune to Poison

Mice are famous for being very adaptable animals; they grow immunity and are resistant to poison very fast. Thus, producers are always developing new substances.

Technically speaking (at least this is the regulation in many countries) retailers should not sell poisons that mice are immune to in the areas where the rodents are known to have developed an immunity to it; this is to avoid the strengthening of their immunity and the proliferation of a population of mice with such resistance.

They tend to be immune to common poisons, like Warfarin, more than others.

If they are eating the bait but you see no changes in their behavior as shown in a previous section, it means that the poison is not working on them, thus you should change it.

Usually, you can check with local authorities if your area is known to have mice with a certain immunity beforehand if you do not want to waste time and risk having poison lying around your home without being consumed.

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