Urban Myth: Mothballs Can Deter Rodents

Another day, another article on a claim that’s frequently made online. Can mothballs deter rodents? If you find a mouse or rat in your house, it’s tempting to want to try everything you can to get rid of them. But do the same things that keep moths away from your favourite jumper work on rodents?

What are mothballs?

Mothballs are basically small balls of pesticide. The active ingredient is usually either paradichlorobenzene or naphthalene. 

What’s the thinking behind using mothballs to deter rodents?

The idea is that when these chemicals react with the air, they give off toxic fumes that are irritating to pests such as rodents. 

Why mothballs don’t work on rats and mice 

You might see anecdotal evidence that mothballs deter rodents, but the main reason they don’t work is that the concentration of pesticides in mothballs is just too small. If you wanted them to have any effect on mice or rats, you would probably need a much higher concentration of chemicals. But before you go out and stock up on a job lot of mothballs, know this. In high concentrations, the chemicals in mothballs become toxic to humans and animals. 

Aside from the fumes being potentially harmful, imagine if your child or pet was to ingest mothballs. Ingestion can cause vomiting, trouble breathing, seizures, kidney and liver damage, and it can even be fatal.

As well as being dangerous, mothballs are an ineffective method of pest control. There’s no point using them outdoors as rain can dissolve them and indoors, as we mentioned, they are at best ineffective against pests. At their worst, they can be toxic or even fatal. If you want to deter or control rodents, your best bet is to stick to what we would always advise:

Keeping your house clean and clutter-free;

Proofing your house against rodents by sealing entry points and gaps;

Using baits and traps if you’ve only seen the odd mouse or rat;

Contacting professional pest control if you suspect there’s an infestation. 

Call Contego to rid your house of rodents

We do not recommend using mothballs to repel mice or any other pest apart from clothes moths. If you have seen signs of a rat or mouse infestation in your house, call in the professionals as soon as possible. Rodents breed quickly and populations can soon get out of hand. They also carry and spread diseases and are more than capable of causing considerable damage to your property.