8 Ways To Tell The Difference Between Slugs And Snails (With Pictures)

by | Slugs, Slugs & Snails, Snails

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If you’ve found something slimy crawling around your vegetable garden or eating your plants, you probably want to know if you have snails or slugs. There are many ways to tell them apart, but here’s the trick to getting it right:

The easiest way to tell the difference between a snail and a slug is to look at the shell. A snail has a shell on its back that’s big enough for its entire body to fit in. A semi slug has a shell that’s too small for its body to fit into. A slug has no visible shell on its back.

Slugs evolved from snails which makes slugs and snails very similar, but there are still some key differences between the two. Let’s take a closer look at these, including their bodies, coloring, and why they live where they live (and where you can find them when you need to).

Table of differences between slugs and snails

Closeup macro shot of a slug or snail face in the grass
Is this a snail or a slug?
Knowing what to look for and the differences between the two will help you decide if you have slugs or snails in your yard.

The table below gives a list of what to look for to tell the difference between a snail and a slug:

ShellMost slugs have a small shell hidden under their skin, and the rest have no shell at all.
A semi slug is a slug with a shell that’s too small to fit its body. They are still classified as slugs.
A snail has a shell on its back that’s big enough to fit the entire body inside.
Snail babies are born with soft shells that grow harder from the calcium they eat.
 Some slugs thrash their tail as a way to protect themselves from predators. When attacked, these slugs throw their tail from side to side to scare the predator and get away.
If the slug is in the predator’s mouth, the predator might get a fright and drop the slug in the bush and lose it.
A snail’s shell helps to protect it from predators and extreme weather, like snow. When under threat, the snail pulls its body into the shell.
There is only one type of land snail (ovachlamys fulgens, aka jumping snails) that can thrash its tail and jump around for protection.
 Slugs without shells don’t need much or any calcium-rich sources as they don’t have a shell to grow and keep strong.
Even though semi slugs have a small shell on their back and some slugs have a shell hidden under their skin, they still don’t need much calcium as their shells are so small.  
Snails need to live in areas with calcium-rich soil or other calcium sources because they need calcium to grow and maintain a strong, healthy shell.
Snails mostly get calcium from the soil, but they also get it by eating leafy green vegetables, leaves, wood, nematodes, fungi, algae, tree and plant sap, animal droppings, animal carcasses, snail shells, bones, antlers, limestone, walls, and rocks.
BodyA slug’s body can be shades of gray, black, orange, or yellow (the banana slug).
Water slugs are a lot more colorful than land slugs, who need to be bland enough to blend in with the soil and bark around them.  
Most snails have a gray body, which can be light gray, dark gray, or any shade in between.
Common garden snails have a brown shell, but a snail’s shell can also be a mixture of white, black, blue, yellow, silver, or red.
Shells may be striped or speckled.
 Slugs keep their internal organs inside their body. This takes up space and makes a slug’s body less flexible and agile, so it can’t move its body from side to side as easily as a snail can.Snails keep their internal organs in their shell, so they can sway and turn their body a lot more as they move around.
 Slugs leave a thin solid line of mucus behind them as they crawl because their body is quite stiff and stays fairly straight.Because a snail’s body is more flexible and the snail uses waves of muscle contractions to move forward, it either leaves behind a thick line of mucus or a thick dotted line of mucus.
Hiding PlacesSlugs sleep during the day, and they can hide in spaces that are too small for snails to fit with their shells. Look for slugs under:
– ground cover
– loose bark on tree trunks or branches
– boards
– logs
– pots or containers
– stones
Slugs also hide wherever they find cracks or crevices.
Most snails sleep during the day and come out to feed at night, but they also come out during the day after rain.
Look for sleeping snails in dark, damp places like under decks, planters, windowsills, logs, or stones. Snails also like to climb up walls, trees, and fence posts.
Need For MoistureSlugs need to live in areas with a lot of moisture in the air or water to stay alive, otherwise their body dries out.
If things get too hot and dry, slugs bury themselves deep in the soil.
Snails also need humidity and moisture to stay alive, but if they don’t get enough, they climb up walls to find humidity or they seal themselves off in their shell to stay alive.
So snails can survive in much drier climates than slugs.

Pictures and videos showing the differences between slugs and snails

The picture below is a slug, with labels to show you what a slug looks like and what to look for when you are trying to identify a slug:

Photo of a slug with labels on how to know you are looking at a slug
A slug has no visible shell or a small shell that isn’t big enough for its body to hide inside. A slug’s body can be any shade of gray, black, orange, or yellow. And it’s a lot less flexible than a snail.

Click here to find out what happened to slugs’ shells.

The picture below is a snail, with labels to show you what a snail looks like and what to look for when you are trying to identify a snail:

Photo of a snail with labels on how to know you are looking at a snail
A snail has a shell that’s big enough to fit its body inside. The organs are inside this shell, so the body stays muscular and flexible. Most snails have a gray body.

The following video is a fun race between a slug (at the top) and a snail (at the bottom). It’s not at all scientific, but it does show you how slowly slugs and snails move and how a slug’s body tends to be stiff and straight as it moves along, while a snail can swing its body quite easily to the side.

This is because a snail’s organs are in its shell, leaving its body strong and flexible. A slug’s organs are kept inside its body, making the body stiffer and less flexible…

How to get rid of slugs and snails

If you want to get rid of slugs and snails in your yard, below are the best tips and recommended products from Amazon to get the job done:

  • To make sure you have slugs or snails, look for them or look for the shiny, silvery mucus trails they leave behind.
  • If you have slugs or snails in your yard, sprinkle these organic snail and slug killer granules to draw them out of hiding and kill them. The good things about these granules are they’re biodegradable, safe to use around pets, children, and wildlife, and are effective in all types of weather (even rain).
  • If you have a problem with slugs or snails on certain plants or in certain areas, spray the plant or area with this non-toxic slug and snail repellent made with essential oils. This spray can be used indoors or outdoors, and even around the perimeter of your yard to keep slugs and snails out.
  • In the evening, water your garden well and set a beer trap by putting a small plastic bowl in the ground near the plants the slugs or snails are eating. Put the bowl deep enough to leave 1 inch above the ground or cover the trap with a loose lid to stop insects from falling in. Fill the bowl halfway with fresh beer. Empty it out and put fresh beer in every night until you no longer find slugs or snails in the morning. If you don’t want to make your own beer trap, you can buy beer traps from Amazon.
  • A DIY option is to go out and pick up slugs and snails with your hands (I suggest wearing gloves for this). The best time to look for slugs and snails is after sunset and rainfall. Throw the slugs or snails on the ground and stand on them or crush them with a rock. Or throw them into a bucket of soapy water to drown them.
  • If you have rose slugs, try making this dish soap spray and follow the instructions to kill the slugs with a direct spray of the soapy solution.

Click here for my full article on how to stop slugs from eating your plants.

I'm Monique. I love gardening and spending time in my backyard growing things. Here's where I share what I know about backyard pests and what to do about them, so you can enjoy your yard too.

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Monique loves gardening and spending time in her backyard, where she grows flowers, succulents, herbs, fruits, and vegetables.

Monique spends a lot of time researching how to protect her backyard from harmful pests and trying to attract beneficial insects and animals.

She shares everything that she learns and tests here at Backyard Pests.


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