In some cases, fumigation can be an effective short-term method for killing moles and voles. However, there is no guarantee … especially if the affected area is big. This method generally works better with voles than with moles. In any case .. this approach to killing moles and voles does not work long-term … and the animals are often back after 3-12 months … spreading quickly.
An advantage of this method is that it’s fast and easy to do. It’s also relatively cheap … the do-it-yourself version is virtually for free.
Fumigation is one of the least environmentally friendly mole and vole control methods … and is consequently prohibited by law in many places.
How does this method work?
A lethal gas (often carbon monoxide) is introduced into one or several mole or vole holes. The gas spreads through the burrow system … killing those animals that get exposed to it.
If fumigation is carried out by professional pest control companies … the gas it often produced on site via small purpose-built combustion engines. A hose is connected to the exhaust pipe of those engines … through which the gas flows into the mole holes killing the moles.
The do-it-yourself method follows the same approach … but the gas is usually taken from the car, motorbike or lawn mower exhaust pipe.
In either approach … engines are usually left running for 10 – 60 minutes.
How effective is this method at killing moles and voles?
While the gas is very effective at killing moles and voles in principle … the challenge is to have the gas spread to all parts of the underground system. This is almost impossible in large and complex systems. Mole borrows in particular are difficult … as they have many interruptions where the channels are filled with soil.
Professional fumigation generally has a higher success rate. This is partly because the purpose-built fumigation engines are more effective at killing moles and voles. More importantly though … such companies usually know better at what places the gas needs to be introduced. Moreover, they run multiple pipes simultaneously.
Even if fumigation is successful at killing moles and voles short-term … it usually does not help for long. This is because the animals can quickly come back to re-populate the area. Often this happens after 3 – 12 months.
Is this method expensive?
The do-it-yourself method is virtually for free … and hence one of the cheapest approaches to killing moles and voles.
Even professional fumigation is relatively low cost compared to many other methods.
How much effort does this method involve?
Another advantage of fumigation is that it’s relatively fast and easy to do. Even the do-it-yourself approach can be done in less than in an hour.
While this method is not much effort in principle … it has to be considered that having to do it every few months can become quite a nuisance.
Environmental, animal and safety matters
Fumigation is one of the worst approaches to mole and vole control in this respect.
Whilst the death of the animals is quite fast and painless … the biggest problem is that the gas does not just kill the moles and voles … but most other animals that come in contact with. Soil and ground-water pollution is another consequence.
This is the main reason why fumigation is not allowed in many places.
Summary of pro’s and con’s
- Fast, easy and cheap to do
- Not effective long-term as animals come back quickly
- Even short-term this method only works in some situations
- Not friendly to the environment
- Illegal in many places
For a complete overview over all 18 vole and mole control methods … see our page: “18 methods for getting rid of voles and moles”