Trying to say something good about slugs and snails is a bit like standing up for child molesters. Slugs and snails are almost universally hated as the menace par excellence of the garden. Every year we spend millions of pounds on pest control to halt their sneaky invasions. Yet not everything about slugs and snails is bad. Slugs and snails do more good than we realise. And they’re teaching us things about ourselves we never thought possible too.
Slugs and snails are gastropods, a term which means stomach foot – not a bad name when you look at one closely. They are part of the order phylum, and share a relationship with oysters and octopuses. Many are aquatic, some are carnivorous, and most are hermaphrodites. Mating behaviour is slow and exotic, each member of the pair impregnating the other by means of a love dart. If necessary, slugs and snails can reproduce by mating with themselves.
Slugs and snails do a grand job of clearing up and recycling dead plant and waste matter and even small animals. The trouble is, they’re just as likely to take a chunk out of our favourite plants as well as our dead ones. Provided they’re able to get their tiny razor sharp teeth into it, they’re not too fussy. Anything goes.
Dealing with slugs and snails tends to be a cruel business, and we usually show them little mercy. Most of us use slug pellets, of which the active ingredient is usually Metaldehyde. The chemical is usually mixed with a wheat base and works on contact or ingestion, causing the slug or snail to over-produce the natural mucus on which is depends and eventually to dehydrate. If not killed outright the slug becomes unable to move and, in warm weather, cooks in the sun. Metaldehyde is poisonous to other creatures too, though not so poisonous as another nasty chemical used in the war against slugs and snails, Methiocarb, which kills just about anything that ingests it.
Another favourite method, partly I suspect because the effect is almost instantaneous and you can watch your enemy terminally writhe, is salt. This also dehydrates the creature, sucking the moisture out of it and causing it to shrivel before your very eyes. But if this horror- flick is to your taste remember that salt also damages plants, so take care you don’t end up doing the work the poor slug or snail had started.
Increasingly popular are natural control methods involving parasites, particularly the nematode, a naturally occurring micro-organism that is already present in the soil only not in enough numbers to do the slug and snail population any damage. Increase the population of nematodes, so the logic goes, and bam! slugs-a-go-go. It’s harmless to other creatures, though slightly less effective on snails which tend to live above ground. So it’s win-win all round (except for the slug).
If you want to invite your slugs and snails to their own wake you can always give them the beer treatment. Popular amongst humans too, this tends to attract slugs by smell, luring them to their doom in a beery cellar, where they drown. It’s an old-fashioned method that has been used for generations, now modernised by some nifty and easy to use slug traps.
Once upon a time I kept Muscovy ducks. These magnificently ugly birds, half way between a duck and a goose, just loved to eat slugs. Watching them was like watching someone chewing a wine gum. Funnily enough not many other birds share this taste, though thrushes are a dab hand at cracking snail shells to get at the juicy flesh. But as mentioned, snails tend to live above ground where they can easily be seen. Slugs tend to avoid dry conditions, so are more likely to be nocturnal. Night loving predators include frogs and toads, lizards, and hedgehogs. But they have their requirements too, such as ponds and dense cover. Still, they’re good to have around, and having slugs and snails too can be an attraction for them.
Only a few of the many varieties of slugs and snails that live in the UK are a problem to us. Unfortunately they are the most common ones, probably because they like to eat the plants we like to grow. So, as so often we have created our own problem. No matter how much bird food we put out, or how many packets of wildflower seeds we sow, our gardens are highly unnatural environments.
The remainder of the gastropod kingdom do a grand job of clearing up dead plant matter and animals. This unseen and unlovely work goes on without our noticing it. If it didn’t we’d find the landscapes we love much untidier and much harder to live with.
And you have to admit, there’s something rather beautiful about snails, and even some slugs. Look closely at a snail shell: see how the whorls spiral out from the centre, the colours shade and contrast. Some shells found on tropical beaches are particularly spectacular, but maybe we overlook some of those closer to home.
Finally, there is another way in which these molluscs – in particular a sea snail with the rather charming name Aplysia Californica – are helping us learn about learning and memory. It seems slugs and snails are smarter than we thought. Scientists have examined the brains of these little creatures to see when proteins linked to memory are released, and a ‘training’ programme has been initiated to coincide with these times. When compared against a control group who received their training at regular twenty minute intervals the experimental group was found to outperform them. The suggestion is that learning experiences that coincide with optimum conditions in the brain can achieve better results; a finding which could have all sorts of implications for the way we teach and learn.
It’s a big jump from the humble slug or snail to the classroom, but maybe not so far as we once thought.
Think of that when next you want to pour salt on them.