We used to have a typical London garden, with a small rockery just outside the patio doors, where lived and lurked many snails (Cornu aspersum). We also had a proper complement of thrushes, amphibians and the odd hedgehog, to help us keep the snaily population down. So I would collect up the snails and throw them down the garden into the middle of the lawn, where I imagined that natural justice would prevail.
My mother – long gone now – would nag at me: “They`ll find their way back – I know they will – they follow their slime trails!” I argued that they could hardly follow their slime trails back when they had flown economy class to their place of execution.. Like every child worth its salt, I was determined to prove my mother wrong.
In the gloom of the night, I collected up all the snails I could find in the rockery, put a Tippex dot under each shell, and placed them carefully at the opposite end of the lawn. Then I went to bed, feeling smug and secure. Four days later, the snails were all back home in the rockery.
Intrigued, I marked off an area two yards square in each corner of the garden. In each area, I collected up all the snails I could find and gave them their own team strip – a blue, yellow, green or red enamel painted dot under the shell. Then I took all four teams to the middle of the lawn, and mixed them thoroughly. Four days later, the snails were all back home in their own corner.
Cease-fire on snail extraditions was instantly called, and I started a monthly check on the numbers of dotty snails in each corner. My mother remarked that it was not only the snails which were dotty. By and large, the snails kept tightly to their own spot. One moved house when I transported a big flower tub to another corner, I suppose because its home ground remained the same – and I found another at the opposite end of the garden. Even in a small, London plot, that seemed amazingly intrepid!
During the winter, the snails slept peacefully, sealing up their front doors against the cold. I wondered if hibernation would spoil their homing instinct, so in Spring I went to look for the teams. Yes – the numbers had dropped a bit, but the majority were still there, smiling sleepily at me when I picked them up. Funny though – there were a few fully-grown but unmarked snails in each corner. If they were so strongly homing, where could they have come from? I came to the conclusion that I had missed them during my initial search, and marked these, and a whole lot of new juveniles, with two dots of the team colour, to differentiate them from last year`s batch.
I could hardly give up now, could I? For the next two years, I fostered the snails in the manner of a keeper at a wildlife park. They were rounded up, counted, recorded, and new ones were marked with the appropriate number of coloured, enamel dots. Then I patted their shells and set them free to graze unpelleted and unpersecuted.
One of the remarkable things was that some snails would live so long – when we finally moved to Hampshire there were still a fair number of the original ones, marked with a single dot, together with the two and three dot ones of subsequent years. I wonder if the new owners are still finding spotty snails, even now?
Our Hampshire garden is twice the size of our London one, and the bottom boundary is marked by a pretty little river, which separates us from a field. I haven`t repeated the snail experiment, but I have changed my disposal tactics in the light of superior knowledge. While I am gardening, I collect slugs and snails up in a bucket, and at close of play I throw them over the river. I am perfectly sure that snails don`t swim, although my neighbour swears they don`t need to – they just take a longer route by walking downstream to the bridge. I am perfectly sure that neither option is open to them – but then again, I was perfectly sure that they wouldn`t find their way home after flying down the garden! Perhaps another experiment is called for...