Rats are often part of the garden, allotment or farm ecosystem.
With plenty of food available in the gardens and in the compost,
lots of habitat and places to build nest or to hide in the surrounding landscape,
and often a lack of natural predators, there isn’t a lot to prevent the increase in rat population.
Or at least that is what I have observed through the many years of managing the RED
Gardens Project, as I have been dealing with rats in and around the gardens for as long as
I have been on this site growing vegetables. I have tried a lot of different methods of
controlling the rat population in the past, which I have talked about a few
times in previous videos, but as with many things my thinking about this controversial
topic has changed over the years. I have also received a fair amount
of criticism about the different methods I use, and people have offered suggestions
about other possibilities or approaches, some of which I have experimented with.
And because so much depends on context, I thought it would be useful to talk about
the 9 ways that I think there are, to deal with rats in and around the spaces we grow vegetables.
Many people are afraid of rats or think that they are disgusting or dangerous, but I think they are
intelligent and quite amazing creatures. As far as I have been able to determine,
the only real danger with rats is the possible spread of Leptospirosis,
or Weil’s Disease, which is dangerous. But it is apparently a water born disease
with the greatest risk of infection being when scratches, wounds or broken skin
come in contact with puddles or bodies of water that rat urine may have washed into.
So it is relatively easy to reduce risk simply by avoiding contact with standing
water in and around the gardens, and by following sensible hygiene practices,
such as covering wounds with waterproof bandages, washing hands, and washing everything we harvest.
And if we can accept that they are not dangerous, or that the risk can be extremely low,
then perhaps the first method, or approach to dealing with rats is to simply tolerate them,
to accept that they are a part of the landscape. And perhaps that they have a right to exist,
and can form part of a natural ecosystem, especially if they can become food for
wild predators within that ecosystem. This sounds great, and could work for
those who grow food on their own property, far enough away from others, but the gardens
I manage are within a larger allotment area, that is shared with many more other people,
which is also publicly accessible. And we have been quite good at creating
a landscape that makes an ideal habitat for many creatures, including rats, with a lot of food in
the gardens and in the numerous compost piles, and a not many natural predators in the area.
These are ideal conditions for a rat population to get much bigger than most people will tolerate.
The second method for dealing with rats is to simply not attract them,
and this is the most common criticism or comment that I get.
It is widely believed that adding cooked foods, meat scraps, oils and other similar items to a
compost pile will attract rats, and it is probably true that rats are less likely to eat a discarded
carrot, potato peel or apple if stale bread or the remains of cooked rice are available.
But rats are opportunistic omnivores and will eat many things, including a lot of the vegetable
scraps and other things that typically end up in the compost pile, and will even eat the worms that
often come in to help with the decomposition. I have found that the rats are attracted to a
compost pile even if we avoid adding anything that is typically seen as potentially attracting them,
and they seem to like making their burrows or nests in the partially decomposed compost piles,
where its is often warm, and safe, and close to lots of food, especially in the winter.
I encourage people to add all of these types of normally restricted decomposable material
to the community composting facility that I manage, partially to reduce the need
for people to manage a compost pile closer to their home, where rats may be more of an issue.
But I also think that we need to find ways to managing all food wastes, including cooked foods,
to recycle the nutrients back into compost for feeding the vegetables in our gardens,
rather than sending this nutrient rich material somewhere else.
It is of course possible to build a compost pile that rats can’t get into, and this is
another potential way to deal with rats. A friend and neighbour has built a compost
pile like this that works quite well, with welded wire sides, concrete pavers around
the base and a hinged top to prevent rats from coming in, and there are other possible options.
This will restrict their food supplies, and reduces possible places for them to
build their nests, which will probably slow down the population growth a bit.
But without other measures, the rats will still be there, and find somewhere else to live,
and end up eating a lot more of the vegetables in the gardens.
I have seen rats remove a lot pea pods from the gardens,
eat most of a crop of young beetroot and the tops of many carrots, dig up many of
the bean and pea seeds that we planted, hollow out a squash to get at the seeds,
eat all the microgreen seeds, and will happily munch on the low hanging tomatoes.
I’d rather they ate whatever was in the compost pile and stayed away from everything in the
gardens, but for many people keeping the rats out of the compost is a first big step, and in some
contexts it might be enough to adequately deal with rats, but I think it would take additional
measures to prevent them from thriving by eating what we are growing in the gardens.
Traps are one of the most common and obvious solution for dealing with rats, and I have
tried a lot of different types of traps. The standard wire snap traps can be effective,
though after a few are killed, the others seem to recognise the danger,
and they are much less attractive to the rats if other sources of food are around.
They are not always effective at killing the rats quickly, as I have found some traps
dragged quite a distance, or with still living and suffering rats a few times,
and a few birds have been caught as well, so I generally don’t use traps like this.
I have tried live traps a few times years ago, but then I need to either kill the occupant,
or set it loose far enough away to become someone else problem.
I have rigged up a few traps that have a flap that drops the rats into a bucket,
and they work occasionally but cause a fair amount of suffering for the rats,
and I generally still have to kill them. The main issue with all bait types of
traps is that they are much less effective if there are other sources of food around,
which is often the case in a garden, even the more expensive humane trap that I bought in to try.
This trap has a special bait, and a wire that triggers a deadbolt powered
by a small CO2 cartridge, which kills the rat instantly, and the trap automatically resets.
It has killed a few rats since I bought it, but not enough in my context to justify the cost,
because if I place it close to any other food source, the rats seem to just ignore it.
Poison is the other very common method of killing rats, unfortunately way too common,
as the poison can also kill any predators that catch and eat the rats.
I avoid using conventional poisons because of this potential for collateral damage, but a few years
ago I tried using different types of bait that I mixed myself that contain a lot of baking soda,
which apparently reacts in the stomach of the rat to produce enough gas to eventually kill the rat.
Or there is a version with plaster that apparently kills the rat by
hardening in the stomach without the risk of injuring anything else.
I know the rats ate the bait, and I did see some of the rats appearing to be suffering,
and I assume they died eventually, so this type of bait seems to work, and may be appropriate
in some contexts, but I would rather use other methods, to avoid the possible extended suffering.
After using bait like this, and when using traps, I have noticed a few times when very
young rats were out searching for food, and I suspect that the adults had been killed
leaving the very young to fend for themselves. And I think that this is probably an issue with
any method that only kills the adults that are out wandering in the gardens, potentially leaving the
tiny occupants of the nest to die of starvation, or to wander around desperate for food.
Using predators to keep the rat population down is another very effective method,
and cats are the most obvious option. But in my context, where the gardens are on shared
land away from our house, I am hesitant to keep cats around the gardens for rat control, and cats
also kill a lot of other creatures that I would prefer to have around the gardens, especially if I
keep the cats hungry enough to deal with the rats. There are a few cats in the community that
regularly pass through the gardens, and some of them hang around for a bit,
but they don’t seem to be overly curious about the rat nests and rat runs.
And I got footage of at least one cat that was much more interested in the content of
the compost, and didn’t seem interested in the rat close by, and the rat didn’t seem too be
too bothered either, so obviously not all cats are good for controlling the rat population.
We do have a few wild predators in the area, including foxes who pass through the gardens
regularly, owls in the woodland nearby, and birds of prey that are large enough to catch a rat.
A number of years ago I decided to stop trying to deal with the rats in and around the gardens,
to see if these wild and domestic predators would be able to stabilise the rat population.
No doubt the predators were killing some rats but not enough to keep the population at a level the
was acceptable to the other users of the area, and I eventually had to take control again.
Hunting is another option, and although I don’t have a gun, or live in an area where guns are
common, it is apparently a popular way to keep rats under control in other places.
Other people seem to have a lot of success using ferrets to hunt and kill rats in their burrows,
but I don’t know anyone who does that around here. But I used to hunt rats with my neighbour’s dog
years ago, where the dog would catch any rats that ran out of the compost piles that I was turning.
The rats were obviously panicked for quite a while as their burrows were dug out,
and when they eventually tried to escape, the dog killed most of them really quickly.
Working with a dog like that was an effective method, until he got too old,
but it did require me to put in the effort to turn the compost,
or at least to dig out the rat nest, which was not a quick or easy task.
But it did make me realise that it was a lot more effective to see the compost piles as
large rat traps, as it was much more effective and easy to find and dig out the rat nests if
they were in the maturing compost piles. And the rats seemed to like make in their
nests in these loose, slightly warm piles, especially if they were covered with something,
and they were also really close to an abundant source of food that I didn’t mind the rats eating.
This was a big change for me, to start to see the compost piles as a place that I wanted to
attract the rats to, rather than trying to keep them away, as they were much easier to
control and less of a problem if they built their nests in the compost piles, rather than
hidden somewhere in the surrounding landscape. When my neighbour’s dog got too old to help
with this grim task, I decided to try to do it myself, to try to trap and kill the rats as they
tried to escape when I was turning the compost piles that they had built their burrows in.
This generally required the compost to be in a container of some kind,
where the rats could get in but I could seal off their burrows, or it involved building some
kind of temporary enclosure around the site, where I could close off any escape routes.
Once I figured out how to set up the enclosures and developed the necessary skills, this became
a reasonably effective way of killing most of the occupants of a rats’ nest,
but it was quite gruesome at times, and I wasn’t as effective at dispatching the
rats as my canine companion had been. So I was really glad to find a much
more effective way to deal with a nest of rats without being so intimately involved.
The method I have been mainly using to deal with rats for the last few years has been
to asphyxiate them in their burrows or nests. I first heard of this possibility with people
putting dry ice in the entrance of rats nests, which would apparently fill the
burrows with a high enough concentration of CO2 gas to kill all the rats in the nest.
I have also heard of people attaching one end of a hose to the exhaust of their car,
and placing the other end in the burrow of a rats’ nest, to essentially do the same thing.
But the compost and gardens are not easily accessible by a vehicle,
and dry ice seems to be an expensive and inconvenient option around here.
But that got me thinking about the possibility of using my propane powered flame weeding torch
to fill the burrows with enough CO2 as well as smoke and other problematic
gasses to kill all of the rats trapped inside. I have found this to be a really effective way
to manage the rat population, more effective in my context than any other method I have used.
Whenever I come across signs of a rats’ nest,
I try to locate and seal up all of the entrances, except one.
And then I run the flame of the torch into the remaining burrow entrance for a few minutes,
then seal it up, trapping the rats in with the smoke, carbon dioxide, carbon monoxide,
and without enough oxygen to survive. It isn’t a perfect method, as some rats do escape,
especially if I don’t find all the entrances of the nest, or seal them up effectively enough.
And I would not use it in the context where there could be a fire risk,
and it is not effective where the nest can’t be sealed up enough, but if I can seal it up,
then it only takes a few minutes to kill all the rats in the nest, including all of the young.
One of the main criticisms I have got about this method, is that I am burning the rats alive,
which I didn’t think was the case as the burrows are usually quite big, but I wanted to be sure.
So I put a compost thermometer into one burrow entrance that I covered with a
rock, and used the torch in another entrance to see how hot it would get.
I was able to see the smoke escape around the rock, indicating that the burrow quickly
filled with smoke, but the temperature didn’t get much above 50ºC or 120ºF.
It would have been hotter in the parts of the burrow that were closer to the flame,
or if I kept the torch on for a lot longer, but I figure the rats would naturally try to get as
far away from the heat and noise as possible, and it would be hot, but not hot enough to
kill them, they would die of asphyxiation. Recently someone suggested using argon gas,
which is an inert gas commonly used in welding, and apparently quite a bit heavier than air, and
if I released enough gas into the entrance of the rat nest, the gas would sink into the burrow, and
displace the oxygen, and asphyxiating the rats. Or canisters of CO2 gas could possibly do the same
thing, without the heat or smoke or flame, but I haven’t tried using either of these options yet.
I am not in the context where I can simply let the rats live in the area around the gardens,
and there don’t seem to be enough natural predators around.
If I don’t want to keep a few hungry cats up in the area of the gardens, then I need to take on
responsibility for keeping the rat population to a low enough level so that they aren’t a problem.
And if I am going to kill the rats, I don’t want to risk killing other things,
and it would be better to try to reduce the amount of suffering, with them dying fairly quickly.
And whatever methods I use need to be effective compared to the amount of time and effort that I
put in, and preferably quick and easy so that I am more likely to do it more frequently, to
prevent the rat population from expanding rapidly. In my context, with a shared site away from the
houses, I find it easiest to attract the rats to the compost, and away from the vegetables in
the gardens, and to encourage them to build their nests in the maturing compost piles.
This makes it a lot easier to find and asphyxiate the whole nest,
and this has been the most effective way I have used to keep the rat population under control.
And if I am persistent, and deal with the nests as soon as I find them,
the population in the area stays at a really low level,
and there is no longer any damage to the vegetables in the gardens.
Because I already have the torch for flame weeding, it is the easiest and most convenient
method that I have to asphyxiate the rat nests, but I think using canisters of argon and CO2 gas,
may be more effective, or perhaps cause less panic and suffering.
There are of course other ways that I could manage the rat population including making rat
proof compost containers, which would make using bait type traps a lot more effective, and then
to asphyxiate any nests that I do come across. This would probably work well as a combination,
and as is often the case, it’s generally more successful to use several methods,
rather than just relying on one. And in other contexts, especially
if I lived in an urban environment, or if I grew food on my own land far away from other people,
I would probably rely on a very different range of methods to control the rat population.
But, in the context I am in, this method has worked really well.