Does Mouse Poison Expire?

does mouse poison expire

When a poison expires does it get more or less poisonous? What about mouse poison – can it expire? Yes and no, it depends on how well you preserve it. If the mouse poison, or rodenticide, is not well preserved, it will still be efficient, yet unattractive to mice and other rodents. There aren’t usually the expiration dates on mouse poison boxes, yet it surely can become unattractive to mice.

On the other hand, if there is an expiration date, and you keep the mouse poison as instructed below, it will last longer and can be used after the expiration date. It certainly isn’t made for eating, and the expiration just means that the poison isn’t appealing to mice anymore. That certainly can happen before the marked expiration date if you do not keep the mouse poison as recommended.

The preservation of mouse poison

  • You shouldn’t keep the bag with poison in a basement or any other room that is humid. The humidity will soften your poison and this way it will become unattractive for mice.
  • The mouse poison shouldn’t be kept nearby other poisons such as pesticides, herbicides and other chemicals. The smell of the chemicals will be repulsive for the mice. Therefore they won’t eat it.
  • You shouldn’t keep mouse poison near the source of heat. If the place where you keep the poison is too hot, it can induce some chemical reactions and spoil the poison.

Following these instructions, you need to keep your mouse poison in a dry and cold place with no other chemicals in the vicinity.

If you keep your mouse poison this way, it will last for years. Even after a decade it will still work if the pests still find it attractive. Otherwise, if the aroma of the mouse poison has weakened, the mouse won’t find it appealing to eat at all.

Yet, the mouse poison is still harmful and useful if you mix it with other substances that appeal to the mice. For instance, peanut butter or other nutty products.

But be sure to read the instructions carefully because some sorts of the mouse poison cannot be mixed with any other substance.

Be cautious though!Some mouse poisonsare lethal as for the mouse, so for the pets and humans. Therefore, keep it away from any animal and household members, especially children or psychically unstable persons.

Mouse poison on duty

If you already set the mouse poison on the surrounding in order to catch a mouse you should follow simple rules of preservation.

  • Do not put the mouse poison in the wet areas. This way you will destroy the poison and it won’t be attractive for the mice anymore.
  • Change your poison regularly. The appealing smell, which is included in most of the mouse poison,disappears faster when it is on the open ground. So it takes probably a week or two for the odor to disappear,depending on the kind of poison. Because of this, you should change your poison weekly.
  • Be sure that you have put the right dose. If you put too little, it won’t be enough for mice to smell it and to grab it. Even if they grab it, it won’t be enough to kill the pest. On the other hand, if you put too much of poison, it will make a mouse suspicious and it won’t take it. It will cause the bait shyness. Therefore you need to read the instruction carefully because the dosage depends on the type of mouse poison.

Be patient, because most of the mouse poisons take a few days of constant eating to cause the death of a rodent. Therefore, you should check the surrounding regularly, but without moving any baits or poisons. If you move it, you will scare the mice.


For the conclusion, the mouse poison does not expire but it is useful for as long as it is attractive for the rodents. So, if you are willing to keep it as suggested, it will last for a decade, until the attractive smell disappears.

Some sorts of mouse poisons can be used together with bait. Even then, after a decade, the mouse poison can decrease its toxicity and be used only with in higher dosages.

Be careful because some types of mouse poison do not work well with the bait, and they shouldn’t be mixed.  In that case, after the odor disappears, you can say that the poison is unusable. Yet, it doesn’t mean that the poison isn’t lethal anymore, and if you want to dispose of it, you should do it carefully.

Leave a Comment

Your email address will not be published. Required fields are marked *