How to identify: the Leopard Slug

A Leopard slug; copyright Roy Anderson

Common name: Leopard Slug
Scientific name: Limax maximus

Why are we looking for it?

The Leopard Slug is thought to be widespread in the UK, but there are relatively few records of where it actually occurs.

Learning more about where this species is found, and in what numbers, will add to our knowledge of the species. It will also help us monitor how populations change in the future. How common is it and do urban areas provide a suitable habitat?

Identification features

  • Up to 16cm long when fully grown
  • Brown or grey, with brown or black spots/blotches
  • Front of body has marbled pattern of spots (never stripes)
  • Back of body has up to three dark stripes on each side
       – dark stripes may be broken up into a line of dots
  • Underneath (sole) is white
  • Their slime is particularly sticky

Identification tips

Could be confused with…
Other slugs when young (less than 7cm long). Submitting a photo with your record allows us to check this.

Where can I find it?
Across the UK, in woodlands, hedgerows, parks and gardens that have old trees or dead wood lying on the ground. It has even been found in damp cellars and sheds.

Look close to the ground in damp places, particularly under logs and stones.

When can I find it?
All-year round.


Leopard Slugs eat fungi, rotting plants and even other slugs. They need to keep their bodies damp in order to breathe, so are usually found in dark, damp places, particularly among rotting logs.

They are hermaphrodites, meaning that each slug has both male and female sexual organs. They still need to mate with another individual though and have quite a spectacular way of doing this. The two slugs climb a tree or other structure, then hang from a branch on a thick strand of mucus, intertwined with one another. After mating, each slug lays clutches of transparent, round eggs in damp places.

Leopard Slugs can live for several years.

What does it do for us?

Leopard Slugs are a gardener’s friend. They don’t damage healthy, living plants, but they do eat other slugs, including species that can damage garden plants and vegetables. By eating dead and rotting plants, as well as fungi, Leopard Slugs recycle nutrients and fertilise the soil.

Try to encourage this helpful slug by creating a log pile – damp, rotting wood provides ideal conditions for it to live and breed.

Interesting fact

Leopard Slugs have a small disc of shell inside their body. Slugs evolved from snails and this disc is a remnant of what used to be the snail’s shell.


Think you've seen one?

Leopard SlugTake a photo and complete our simple online form to help us learn more about their distribution.

Submit a sighting

Where have they been seen?

UK mapExplore our interactive map and see where the Leopard Slug has been recorded so far.

Species Quest results map


Need help with identification?

Simply upload a picture of your find to iSpot or the Natural History Museum's Bug forum and an online community of experts and enthusiasts will do their best to identify it.

Visit the iSpot website

Visit the Bug forum on the Natural History Museum's website