Interesting Facts about Slugs and Snails
At any time 95% of the slugs in your garden are underground
There are approximately 40 species of slug currently found in the UK, with only a small number of these considered as pest species. For 95% of the time slugs live underground or in woodpiles or under damp vegetation.
Whilst slugs don’t hibernate, snails do. Lift some pots during the winter you’re likely to find lots of snails hibernating
The Evolution of Gastropods
Slugs have evolved from snails. Snails have a kind of exoskeleton in the form of a shell, with the ability to retreat into it for hibernating, in danger, or if it gets too hot or dry.
All terrestrial slugs have evolved directly from terrestrial snails; with the most obvious evolutionary shift being the loss of their large external protective shells; however modern slug species do still have a vestigial shell, a remnant left over from their evolutionary past. This shell is still found externally in a small number of UK species, however, in the majority, it is now located internally.
Asexuality
Slugs have both male and female genitalia. If there are no suitable mates, slugs can impregnate themselves. When two slugs mate, both get pregnant as they exchange sperm.
Slugs partially encircle one another, then their male genitalia appears from beneath their mantles. The male parts of the slugs join together in a kind of corkscrew to exchange sperm. However, they frequently get stuck like this. Then one slug will chew off the penis of its partner or even its own to get “unstuck”. The victim, however, can survive with just female genitalia and can continue to breed.
90,000 Grandchildren
A single slug lays up to 100 eggs several times each year. And bearing in mind that, mostly, when slugs mate, both get pregnant, you can see how quickly 1000s of slugs can appear. A single slug can accumulate a staggering 90,000 descendants during its lifetime. Snails too lay up to 100 eggs several times a year
Laying in wait
Slug eggs are those tiny pearly white balls you find in the soil as you dig. Small, round, delicate, and easy to squish. But they are remarkably resilient. Slug eggs can lay dormant for years and only begin to hatch when conditions are optimal. So, even if you’re sure you’re totally on top of controlling slugs naturally, there can, in fact, be thousands of eggs in your soil, just waiting for the perfect conditions.
Teeth
Yes, slugs have teeth. 27,000 teeth to be precise and garden snails typically have about 14000. They use this ridiculous number of teeth to rasp away at their food, hence they leave such ragged holes in leaves. Who would think that a slug has more teeth than a shark? And, just like sharks, slugs regularly lose and replace teeth.
Stomach Foot
Slugs and snails are gastropods. Which literally means stomach foot. The foot, which is the flat bottom side of the slug, is essentially a powerful muscle. This muscle contracts in rhythmic waves while the slug secretes the notorious slime at the same time. This allows the slug to glide across the slime as its foot contracts.
Surprisingly Stretchy
Disturbingly, slugs can stretch to 20 times their standard length at will. That’s why it’s so difficult to keep slugs out of specific areas. They can stretch out and wriggle through tiny holes.
Snails climb up house walls to get away from predators and avoid being stood on. They also climb walls to look for food or even eat the walls. The weather has a big influence on snails, and they often climb walls as the seasons’ change, to cool down, find moisture, or escape the cold.
The Point of Slime
Whilst we might not like slug and snail slime it is vital for them. The ability to move depends on it. For each slug, its slime is equivalent to our fingerprint. Their trail enables them to leave and return to their chosen shelter and to get back to the particular food they have found.
The slime contains fibres that make it sticky, which enables them to climb almost any vertical climb on almost any surface. Their slime is highly absorbent, so water just makes it more effective. This is what makes it so difficult to wash off your hands. If you are struggling, then use vinegar.
Confusing a snail
Snails are slow movers, typically about a metre an hour, although they seem to have a knack for disappearing really quickly. In a Chris Packham documentary, an experiment on snails showed that they have a homing instinct. When plucked out of their habitat and place in the centre of a large lawn, the majority returned to the quarter of the garden they came from. The test group imported from Cornwall just rehomed themselves randomly through the garden. If you are collecting snails and planning to rehome them you might want to take them quite away from your garden.
Greedy eaters
And don’t some of us know it? Slugs consume around forty times their weight in one day.
Out partying all night
Most of the snail and slug species prefer wet and dark conditions. Go out into your garden in the late evening when it has rained and there’s a good chance you find masses of slugs and snails. They tend to only come out in the day if there is no sun
Green Blood
If you start skewering slugs or decapitating them as a natural method of control, or, if you accidentally squish one under your boot, you’ll see that they exude green-yellowish blood. This is due to the molecule, hemocyanin, that transports oxygen in slugs.
Danger to dogs
Snails can be an issue for dog owners as some snails carry a parasite called angiostrongylus vasorum affects dogs’ heart rate, which can even be fatal.
Snails and slugs hate salt
Snails are highly intolerant to salt, and if you spray them with this white substance, they will die. Some people will take a strong salt solution and drop the slugs and snails into it. This kills them by dehydrating them. The problem for your garden is the salt. Your compost will not like lots of salt being poured into it and nor will your soil like it if you just sprinkle the salt on them. Beer is probably a better solution.
Choosing carefully what you grow
Growing lettuce anywhere in the world it’s going to be a hard job to do because snails are everywhere. Experiment with different types of lettuce as some survive better than others. Snails and slugs are most active in wet weather, so if you live in a rainy area, you will never get rid of them.
Slugs and snails as pollinators
Pollination done by snails is called malacophily, the fact there is a word for it means it actually happens. Slugs are known to pollinate wild ginger and Trillum flowers. Remarkably, they do their pollination services when most insect pollinators are inactive, that is, during the nights and rainy days, when the slugs are most active. Research showed that the snail species Lamellaxis gracilis pollinates Volvulopsis nummularium, which belongs to the morning glory/ sweet potato family.