Those Unsung Heroes - Snails and Slugs

Slugs Poo From Their Heads Using The Same Structure From Which They Breathe. Evolution… You Had ONE Job.

Yes, I know. I often write about the underdog in the ecosystem. Beneficials in the garden like lady beetles, bees, and butterflies are an easy sell, but the slimy underbelly of the ecosystem society as a whole are deserving of their accolades, and as annoying as they can be they do serve a purpose, and that includes slugs and snails. 

Now before you start throwing sharp objects at the computer screen ( I can hear the yelling and screaming from here ) hear me out.  I know that they have a bad reputation but I’m here to convince you that they are misunderstood, scorned creatures, and a key part of the ecosystem.

Snail Vs. Slug - Destruction By Any Other Name….. You Get The Point

First of all let's define a slug vs. a snail. Is a slug simply a snail without a shell? Yes and no. Slugs, the cousins of snails, have evolved so that the shell has become smaller or has completely become absorbed into the body and they can survive without them. Snails carry all their internal organs in the shell, so you can’t just take the shell off the snail and make it a slug. So these gastropods, a class within the mollusk family, aren’t exactly the same, not to mention the semi-slug, that third cousin in the family nobody can quite explain. But I digress, they all serve similar purposes other than being one of the most annoying pests in the garden.

According to Arizona Game and Fish, “Arizona is home to nearly 200 species of native snails and slugs.” 1 I’ve been fairly lucky in my dry Scottsdale garden, but have had one or two come in on plants I purchased elsewhere and didn’t discover them until their grim destruction was complete. And what did they eat? Almost every little seedling I’d planted in that bed and their slime trail led down the side of that bed and into another and the strawberry devastation was enough to cry about. Pretty speedy for something with a name like snail.

But Let’s Not Focus On The Bad

Like the mighty pill bug (yes, I hear you groaning), these slimy little creatures feed on garden debris and rotting vegetation, as well as excrement (a nod to the dung beetle) and animal carcasses…..hopefully you don’t have a lot of those in your garden, but each to his own.

They’re a key player in the decomposition process and champions of recycling nutrients into the soil through their feces. They’re also known to be pollinators, albeit the world’s slowest and least efficient. The empty snail shells provide homes for other insect species, typically solitary bees will lay their eggs in the shells and seal them shut until the young adults emerge. Although I could have lived without this little gem of knowledge, a dear friend of mine told me that snail slime is used in skin products and cosmetics. 2 It’s all true.

As to escargot, the brown garden snail, not native to North America, hails from Europe and was brought over by people who thought they would become a popular food item. The facts are a bit shady but somehow these snails made a break for it and have become a very invasive garden nuisance. Though not my favorite item on a menu - geese and ducks think they’re the best thing ever and they’re not the only ones. Apparently chickens, toads, turtles, birds, and some beetles think they’re tasty as well.

Controls

In researching how to control snails and slugs in the garden there were more home remedies and crazy suggestions than I can even mention here… one person recommended an electric shock wire around the garden. But according to the University of Arizona Cooperative Extension there are many forms that are effective including hand picking, non-chemical trapping, barriers, chemical baits (not to be used around dogs, cats, wildlife, chickens, ducks, etc) and natural enemies. 3

Calling them marvelous may be a stretch but the next time you see a snail or slug take a moment to recognize the silent contribution to the natural world then throw them to the chickens.

Crazy Fun Facts 

1. Slug blood is blue because rather than using iron to carry oxygen, slugs use copper which turns blue.
2. Some slugs can grow up to a foot long!
3. The fastest slug has been clocked at the breakneck speed of 29.4 centimeters per hour which is 11.57 inches. Just a note - they don’t really have necks so I question the validity of this fact!
4. Slugs can mate with themselves as they have both the male and female reproductive organs.
5. A slug has between 2,000 ad 8,000 teeth to rasp food away like a cheese grater.
6. The lemon slug is only found in established woodland and is known as an indicator species for scientists because its presence indicates the age and health of the woodland.
7. You need to use vinegar to scrub slime off surfaces. In this way you eliminate the snail trail others will follow into your garden.
8. And finally, slugs poo from their heads using the same structure from which they breath. Evolution… you had one job.

 

1. https://volunteer.azgfd.gov/agency/detail/?agency_id=155986#:~:text=Yes, indeed!,and neighboring towns and cities.
2. https://www.webmd.com/beauty/what-is-snail-mucin
3. https://extension.arizona.edu/sites/default/files/attachment/snailsandslugs_1.pdf

Slugs, Quick Facts, W.S. Cranshaw, 1/2013, Colorado State University. https://extension.colostate.edu/topic-areas/insects/slugs-5-515/

Snails and Slugs, Jeff Schalau, 11/12/2023, Adapted From Backyard Gardener Publications, University of Arizona Cooperative Extension, Yavapai County https://extension.arizona.edu/sites/default/files/attachment/SnailsSlugs.pdf

Snails and Slugs, Cindy Watter, 3/14/2021, UC Master Gardener Program of Napa Valley, https://ucanr.edu/blog/napa-master-gardener-column/article/snails-and-slugs