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15 Slimiest Fun Facts About Slugs

It's time for slime! Check out these fascinating slug facts and see how much you know about these crazy creatures!

Beano Facts Team
Last Updated:ย  May 4th 2023

Are you ready to get slimy and learn all about natures slipperiest creature, the slug? Slugs have a bit of a bad reputation as boring and icky, but they're SO much cooler than that! We've got 15 fun facts all about slugs and their weird world, so check it out! Have a look at some colourful underwater slugs, find out how big they can get, and why they only have one foot! And you can check out loads more animal facts here! How about these prickly hedgehog facts? Or for creepy crawly fans, we've got these insect facts! We've also got these outstanding opossum facts!

1. Slugs Are Basically All Water

Slugs are sort of like mini water balloons. They're mostly made up of water, and that's why they look so slimy! Although to be fair, the human body is about 70% water, so we're hardly ones to to talk!

2. They Are Related to Snails

Actually, slugs can be the same species as snails - the only difference is that they don't have a shell to protect them! They're also related to other gastropods like shellfish. There are thousands of different types of slug, and some we haven't actually discovered yet!

3. It's Not Slime, It's Mucus

Technically that slimy stuff slugs secrete? It's mucus (Yup, like the stuff up your nose) and they need it to stay alive! Slugs need to keep hydrated, and because they don't have a shell, they're extra vulnerable to drying out (We all hate getting dry skin, right?). So they're mucus gives them a moist layer of protection. That's also why you often see them after its rained - it's much safer for them to move about in a wet environment!

4. A Slug Isn't Actually A Species

A slug is actually just a term for any gastropod mollusc without a shell (otherwise they're called snails) who lives on land. What's a mollusc? Great question! Well, the easiest way to describe it is a slimy animal, who sometimes lives in shells on land or in the sea. Think: shellfish, snails, slugs, stuff like that! They've been around for millions of years and haven't really changed much in that time!

5. A Slug is One Big Foot

A slug's body is basically made up of one giant foot to walk around on! Actually, its whole body is a muscle, and powers it along. It moves by doing a sort of Mexican wave with its body, rippling itself along the ground. How long could you move around like that before you got tired?

6. They Come in Crazy Colours

Common or garden slugs aren't that exciting to look at - unless you're a blackbird - but there are some seriously cool looking slugs out there! Sea slugs in particular have an array of snazzy outfits that come in all colours of the rainbow. Just look at this one - its more like a beautiful alien than a slug!

7. Slugs Can Be Giant!

Land slugs don't tend to get very big, but its a different story under the sea. One of the biggest land slugs is the Limax cinereoniger, which can grow up to 20cm! That's pretty big, for a slug! Sea slugs take cake though;, the Californian black sea hare can is a sea slug that can grow to a METRE long!

8. They Lay Eggs

Slugs reproduce by laying batches of eggs. In order for their eggs to thrive, they lay them in moist places. The eggs also need warmth to develop, and will develop quicker the warmer it is! After they've hatched, they only live for about two years, the first year of which is spent developing.

9. They Have Tentacles

The two pairs of little 'horns' on the top of a snail's head are actually tentacles. They help the slug to do lots of different things. The bigger pair are called the optical tentacles, and they help the slug see. The smaller tentacles are used for feeling and tasting.

10. They Are a Bit of a Pest

Slugs aren't very popular in the UK as they tend to eat lots of things that are important in our fields and gardens. They especially love things like fruit and vegetables, so if you know anyone who grows them, chances are they don't like slugs! But they can also eat a lot of useful things like decaying plant matter and garden waste! That way, everybody wins!

11. But Also a Tasty Snack

Lots of UK wildlife love to eat slugs, especially hedgehogs! Foxes, badgers, birds and other insects also like eating slugs, and if you want to spot those animals, have a look in your garden at night time after its rained - they may be feasting on slugs!

12. They Have a Shell Replacement

Slugs may not have the full on protection of a shell, but they do secretly have a little bit of armour. They have a 'mantle', which is a thicker, more protective layer behind the head that they can retract into if they feel threatened. Smart!

13. They Don't Have Any Bones

Slugs are invertebrates, which means they don't have a backbone - in fact, they don't have any bones at all! They use their muscles (or muscle) to get around instead! Snails don't have a backbone either, but their shell gives them the protection a backbone might.

14. They Have a Nose on Top of Their Heads

If you look closely as a slug, you'll notice they have a little hole on top of their heads. That hole is actually a nose, used for smelling, and they also have another nose, used for breathing...on their tails! Imagine if you had your nose near your feet - you'd be able to smell them, yuck!

15. They Have More Teeth Than a Shark

Yup, that's right, slugs have teeth! Not only do they have teeth - they have thousands of teeth! In fact, they have more teeth than a shark! Slug's teeth are teeny tiny, and called radula, and help them to break up food. They regularly shed and regrow their teeth, which must cost the tooth fairy a lot of money!