Slug Pellets and Their Hazards

Slug pellets should always be used as a ‘last resort’, but I’m telling you about them first because they’re often the gardener’s first (and only) resort.

Despite their popularity, slug pellets are one of the least effective slug control measures, killing no more than 10% of the slug population in your garden. However, they do pose a real hazard to other wildlife, pets and even young children.

Slug pellets are based on one of two active ingredients – Metaldehyde or the less common Methiocarb.

Methiocarb

Methiocarb is about ten times as poisonous as metaldehyde, thus posing far greater danger to other animals. It breaks down more slowly too, making it a longer lasting hazard. It’s also an insecticide, meaning it kills off many other insects too. This includes the friendly slug-eating beetle and the beneficial earthworm. So I really don’t see any place for these horrid methiocarb poisons in the garden shed.

Metaldehyde

Metaldehyde is the more common and less toxic form of slug poison. Whereas methiocarb causes the slug to swell up with fluid and die, metaldehyde damages the mucus cells causing the creature to produce masses of slime and dehydrate. If not killed outright, it’s immobilised and unable to retreat to its daytime shelters. Metaldehyde also affects the slug by contact and absorption whereas methiocarb needs to be ingested.

Being less toxic, metaldehyde is not so fatal to other animals if consumed in small doses. So ALWAYS apply it thinly as directed. One pellet every 10cm (4”) is more than enough to attract a slug, without giving the friendly hedgehog a lethal dose.

Fascinating fact

Metaldehyde was originally used as a solid fuel in the form of meta-tablets. Its slug killing properties were accidentally discovered by farmers in southern France who noticed dead and dying slugs and snails on picnic sites where meta-tablets had been left on the ground.

Slug bait

I once thought the slug a dumb creature; stupid enough to be ‘attracted’ to the poisonous pellets. In fact the active chemical only makes up about 5%, with the majority consisting of other slug luring ingredients such as cereal and yeast. This gives rise to the often used term ‘slug bait’. Pure metaldehyde actually repels slugs. See, they’re not so dumb after all!

Try making your own eco-friendly slug bait from raw oats or bran, either in small heaps or scattered around vulnerable plants. The greedy little blighters bloat themselves up on it, leaving them dehydrated and easy pickings for the birds.

Pets and young children

The formulation of slug pellets is very similar to dried cat or dog food, making it particularly appetising to your beloved pets. The blue colour is meant to deter, but most have eyes bigger than their stomachs! Of all the pet poisonings seen by vets, slug pellets, especially the methiocarb type, cause the majority.

The blue colouring intended to make slug pellets unappealing to birds and animals actually makes them look fascinating to a young child. And what does a toddler do with everything it picks up? It’s straight in the mouth!

Because the active ingredient makes up less than 5%, ingesting a single pellet poses little harm to children or other animals. However, problems arise due to:

• Improper usage – where a person scatters an excessive amount of pellets or forms little heaps. Now a child or animal can consume a more deadly dose.
• Improper storage – where pellets are stored in easily accessible places, in inappropriate containers, or without proper refitting of child proof lids.

The latter is the cause of most instances of slug pellet poisonings.

As with all hazardous substances, I strongly urge you to always keep slug pellets well out of reach and securely sealed in their containers.

Conclusion

There will always be occasional emergencies when nothing else seems to work, but for the most part, isn’t it time to banish slug pellets to the top shelf of the garden shed?

Think about the ineffectiveness of slug pellets as a control method and the harm they can do to birds and animals, then consider the many other eco-friendly mollusc management ideas on this site.

Of course, you could always try the alternative, and far more entertaining, method of deploying those little blue pellets...   as depicted at the top of this website!

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