Scientists find best way to rid a garden of snails

May 16, 2014, University of Exeter
Scientists find best way to rid a garden of snails
The study shows that removing snails by a distance of over 20m is just as effective as killing them. Credit:

( —Gardeners wanting to rid their spring flowerbeds of pesky snails can ditch the beer traps and egg shells and instead develop a strong throwing arm.

This is according to a new study in the journal Physica Scripta, which has used statistical models to show that removing out of the by a distance of over 20 metres or more is just as effective as simply killing them.

According to the researchers, from Queen Mary University of London and The University of Exeter, their results prove that snails are part of larger colonies that live in the garden, and reveal how gardeners can limit the damage the snails impose by nullifying their homing instinct.

Co-author of the study Dr David Dunstan, from Queen Mary University of London, said: "We showed that the number of snails regularly or irregularly visiting a garden is many times greater than the number actually present at any one time in the garden.

"As such, gardeners shouldn't be setting out to eliminate their gardens of snails. To achieve such a feat would require the gardener to rid the whole neighbourhood of snails, which would be a slow process.

"Gardeners should be setting out to minimise the damage done by snails, which our results showed could be quickly achieved by simply removing the snails over 20 metres away.

"A recent poll by the Royal Horticultural Society showed that one-in-five gardeners in the UK have thrown snails into their neighbours' gardens. Whilst our study shows that this may be more beneficial than actually killing them, we believe the gardening community would benefit as a whole by removing the snails to a convenient wasteland rather than passing the burden onto their neighbours."

In 2010, co-author of the study Dr Dave Hodgson, from the Centre for Ecology and Conservation at the University of Exeter's Penryn Campus, discovered along with amateur scientist Ruth Brooks that snails have a homing instinct.

Dr Dunstan's own study began in 2001 when a small suburban garden was being refurbished. Around 120 plants were planted in the early summer and, after a few days, severe damage from snails had been observed.

Rather than kill the snails, the owners systematically removed them from the garden for six months. Each snail that was found had its shell marked and was then thrown five meters over the garden wall into wasteland. All snails that returned to the garden were given an extra mark on their shell whenever they were found.

A total of 416 snails were marked and thrown over the wall 1385 times during the study.

After collecting the results, Dr Dunstan teamed up with Dr Hodgson to statistically analyse the data from his 2001 experiment, using computer simulations to see if the real-life results could be replicated. In the computer model, each of the snails was created as an object set up with a number of different properties and behaviours and were allowed 'to do their own thing'.

The researchers were able to intervene in the computer model at certain times and change different parameters. They found that they were only able to replicate the real-life results if the snails were given a homing instinct.

"A gut feeling, or even a gut certainty, that the data say something is not science. The data must be scientifically demonstrated and the only way we were able to do this was to give the snails a homing instinct," continued Dr Dunstan.

As for the next stage of the research, Dr Dave Hodgson said: "Snails reveal themselves as an abundant, amenable and enigmatic model organism for the study of animal behaviour and statistical modelling. Our plan is to develop snail behaviour studies as a fun teaching exercise for budding scientists of all ages.

"At the University of Exeter we are continuing studies into snail homing behaviour, and the management of snails as pests and as vectors of disease, via projects with Masters students, PhDs and gardeners."

Explore further: Study uncovers the secret lives of UK garden snail

More information: The article is available online:

Related Stories

Study uncovers the secret lives of UK garden snail

August 23, 2013

Researchers track nocturnal snail activity for the first time, using LED lights and time-lapse photography. Snails were tracked over 72 hours, with researchers measuring their speed, distance travelled and exploration habits. ...

Snail study reveals that stress is bad for memory

November 6, 2013

New research on pond snails has revealed that high levels of stress can block memory processes. Researchers from the University of Exeter and the University of Calgary trained snails and found that when they were exposed ...

Jumping snails leap over global warming

July 4, 2013

Snails in the Great Barrier Reef literally jump for their life to avoid predators. But will they be able to maintain these life-saving jumps, with rising sea temperatures? A new study, to be presented at the Society for Experimental ...

Snail genetic tracks reveal ancient human migration

June 19, 2013

Some snails in Ireland and the Pyrenees are genetically almost identical, perhaps because they were carried across the Atlantic during an 8000-year-old human migration. The snail genetics tie in with studies of human genetics ...

Tiny snails survive in bird's digestive system

July 12, 2011

( -- In a recent study published in the Journal of Biogeography, researchers from the Tohoku University in Japan show how 15 percent of the Tornatellides boeningi, or tiny land snail, are able to survive a bird’s ...

Danger lurking below the sand

August 1, 2011

A voracious predator that devours prey larger than itself has been found lurking beneath Queensland's golden sandy beaches.

Recommended for you

Cells lacking nuclei struggle to move in 3-D environments

January 20, 2018

University of North Carolina Lineberger Comprehensive Cancer Center researchers have revealed new details of how the physical properties of the nucleus influence how cells can move around different environments - such as ...

Microbial communities demonstrate high turnover

January 19, 2018

When Mark Twain famously said "If you don't like the weather in New England, just wait a few minutes," he probably didn't anticipate MIT researchers would apply his remark to their microbial research. But a new study does ...


Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) May 16, 2014
Um, and how are you supposed to find all the snails? You are just going to start evolving a breed of snails that is more and more hard to find.
1 / 5 (5) May 16, 2014
Oh please, gather them up & throw them at least 15 feet away from the perimeter of your garden? What hogwash. The critters are after whatever it is you're growing & the colonies all know how to find it no matter how many you relocate, the ones you relocate will simply be replaced by others from the same colony, these critters know how to talk to one another.

The best control method is to broadcast nontoxic soy extract throughout your garden to which they are attracted & when ingested into their digestive tract they die in short order. No toxics to deal with, no poisons, and no spending as much time picking slugs as pulling weeds, and no accidental pitching your slug & snail pickings into your neighbor's gardens if you live that close to one another.

Is this guy a PETA person who thinks slimy little critters like these are some kind of precious resource?

5 / 5 (3) May 16, 2014
we believe the gardening community would benefit as a whole by removing the snails to a convenient wasteland rather than passing the burden onto their neighbours

Especially if the neighbor just throws them back. Everyone has work - no one has a benefit.

Scientists find best way to rid a garden of snails
Create a fast moving garden.
not rated yet May 16, 2014
Hey guys, show some respect! Somehow this fella got this dog published - and all he had to do is buy a case of beer, a tape measure, and tag a few snails!
5 / 5 (2) May 16, 2014
My mother always used this relocation method, although I don't think she could achieve a 20 meter throw. She insisted that throwing them was not going to hurt them. The landing was their problem.
1 / 5 (3) May 16, 2014
She insisted that throwing them was not going to hurt them. The landing was their problem. jumping off tall buildings, after the first bounce, the rest is easy.
1 / 5 (1) May 16, 2014
Don't throw them 20 metres ! Two metres is fine, but into a bucket with salty water. Against a bare brick wall will do, if you don't want to lug a bucket. The 'dawn chorus' will clear such road-kill away.

FWIW, scrunching them underfoot as you hike down garden to return a cat-caught frog to pond-- Well, that works, too !!
1 / 5 (1) May 18, 2014
I find raccoons love to eat snails, but they leave the shells in my cat's water dish! Ecchhh!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.