They’re one of the most despised pests which chomp through your beloved flowers, fruit and veg all year round.

But there is one rare type of slug which gardeners are being warned not to kill – because they are actually beneficial to your garden.

Although many slugs will chew through fresh lettuce crops or make a meal of your strawberry plants, there is one variety of the unpopular molluscs that will leave your fresh crops well alone, and actually help keep your outdoor spaces clean, tidy and free of disease.

Leopard slugs, so named for their distinctive spotty pattern, are not interested in fresh leaves and instead will feast on dead plant matter.

Their diet consists of fungi, dead plans and even dead animals.

What’s more, leopard slugs are the mafia of the slug world, hunting down, killing and eating other slugs too.

It means that leopard slugs are your beneficial garden cleaners, tidying up around your raised beds, in greenhouses and on lawns.

This can even help stop the spread of diseases that pass from dead plants or animals to your healthy crops.

BBC Countryfile says: “If you spot a leopard slug in your garden, don’t despair as this species is not regarded as a plant pest. The preferred diet of the leopard slug is fungi, dead plant or animal matter making it a useful species to have around.

“Easily recognisable with its leopard-like spots, the species can grow up to 16cm and is commonly found in parkland, woodland and gardens.”

This is backed by the Game & Wildlife Conservation Trust, which says: “These guys don’t do much damage to living plants, as they eat mainly dead and rotting vegetation along with fungi, which helps recycle nutrients and fertilise the soil. But the really cool thing about leopard slugs is that they are omnivorous and will hunt down other slugs, overwhelming them with a top speed of 6 in/min.”

So if you spot a leopard slug, don’t squash it or use slug pellets, simply let it go about its day – and your garden will be better off for it.