Snails have homing instinct, amateur scientist discovers
Published 15/09/2010 | 16:18
Gardeners have been advised to dump unwanted snails more than 300ft away from their plants after an amateur scientist discovered the creatures have a homing instinct.
Scientists have previously believed that snails are far too simple to be able to find their way home.
But Ruth Brooks, a 69-year-old grandmother, began an experiment to settle the issue after she became exasperated with the snails in the garden of her home in Devon, England.
The snails had eaten her lettuce, ravaged her petunias, and devastated her beans. She described herself as a “reluctant snail murderer”, having disposed of numerous snails from her garden in a variety of grisly ways over the years.
“I really don’t like killing snails with pellets or salt and I wanted to find a humane way of protecting my garden,” she said.
Embarking on the experiment to establish the snails’ homing distance, Mrs Brooks gathered up the creatures in her garden and marked them with a particular coloured nail varnish. She asked her neighbours to do the same.
The snails were then swapped around and Mrs Brooks made detailed notes of their movements.
She found that snails have a strong homing distance over 30ft, and the longest returning creature travelled 300ft.
David Hodgson, senior lecturer in ecology at Exeter University who assisted with the experiment, said the findings were “amazing”.
“The conventional thinking is that snails are far too simple to be able to find their way home.
“I thought there was no way that these creatures would show a homing instinct in the way that homing pigeons do for example. And yet they do.”
He planned to carry out further research, adding: “They either have some clever mechanism that helps them get home or it is entirely possible that snails are just moving around the landscape. Then when they stumble across a place they come from they just stop.”
Miss Brooks, a retired special needs teacher, has been named Britain’s best amatateur scientist after her work won the BBC Radio 4 project, So You Want To Be A Scientist.
She said: “I've always wanted to know whether the snails that decimate my plants just come back when I move them, and if they do, what is their homing distance?
“I would say that on the evidence that it would be safe to take your snails away beyond 100m or even further. If you put them somewhere nice with some food, you can be almost certain that they won't come back. I shall certainly be following that advice.''