I can't imagine any scenario where they do good. Earthworms, under some circumstances, will eat seedlings too, but slugs are orders of magnitude worse.

They are only good if you raise ducks - ducks consider slugs and snails a delicacy! Since I don't raise ducks, they get dispatched whenever I encounter them. And I bait with Sluggo as well. Doesn't seem to have much of an impact..........there are just as many more back the next day.

IME, snails are way worse than slugs. They can get to places slugs only dream of traveling. No container is safe!

On Long Island the Snails we have commonly in your garden are a foreign species brought over from France, yes the ones used in Cuisine. So If I see em they get sent to their death, Death by being fed to the chickens.

Their carcasses may add a bit of nitrogen to the soil :)

I feel for those of you in damper climates having to constantly deal with them. Most times that I encounter slug problems I can apply Sluggo once and the problem is solved.

https://en.wikipedia.org/wiki/Decollate_snail 

Eats other snails, but also eats earthworms and anything else. And if it runs out of prey, it eats plants.

And legal only in the 7 southern most counties in California.

No. Kill em

https://youtu.be/IcUp78KLHJ0

They are terribly destructive in the garden, but they are also beneficial decomposers (detritivores, like worms, rolly pollies, and millipedes). Of course any that I get in the garden are promptly disptached, but the answer to the question is yes, slugs and snails do have a "grander purpose" if you will, than simply devouring young seedlings and frusterating gardeners.

The main issue with eradicating any pest species is that you leave less food for their natural predators, which can allow for their population to later explode unchecked. I live in the PNW and have found that, contrary to popular belief, I have much less of a slug and snail issue when I leave a thick mulch of leaves on the garden for most of the year (they eat the mulch more than they do the plants, and it gives their predators habitat), and also bait sparingly with iron phosphate only a couple times in the spring and fall. When I work in the garden I find tons of centipedes and empty snail shells and very rarely a live slug or snail.

It must depend on the species you have. The main culprits in my garden do not eat dead leaves. They go for the freshest, tenderest greens they can find.... and they also love flowers buds. The one year I mulched my asparagus with leaves the spears were already in shreds by the time they appeared in spring. They'd been eaten under cover of the mulch.

Floral: yikes, your UK slugs are savage.

I've seen one slug in my yard and garden this year and they haven't even tried to eat any hostas or anything else. It's a newer home (<5 years) so maybe there isn't an established population yet. I'm hoping to keep it that way...

Krystal, your situation must be location dependent :-) Snails here in my Bainbridge Island garden are omnipresent - here year round - and voracious consumers of any plant material they can find. And they can get to things slugs are unable to reach - they climb up the containers I plant all my hostas in (to protect from slugs); I find them up in the branches feeding on the leaves of shrubs and containerized Japanese maples. And nothing is a worse greeting in the morning then to see them 6' up a plate glass window!!

They also will feed on plants slugs tend to avoid - broadleaf evergreen and succulents for example.

I have also not found mulch to be a deterrent from either snails or slugs feeding on newly emerging plants. Rather, it tends to be a good hiding place from sun exposure and predators. Of which there are not all that many and I have no hedgehogs or toads in my garden. Or geese, which consider them delicacies :-))

My solution is to bait often with Sluggo. It helps but only to slow the process - never really to control :-) There are simply too many and they are too prolific in procreating!

I've been battling snails for years! They de-head and kill all my seedlings grown from seed. I tried Sluggo and other products like it and didn't like it's side effects on my plants. The plants tend to turn VERY dark green and get crisper and wrinkled. It doesn't kill the plants, just mutates them for a few weeks before they recover and grow normal again. I wonder if it's the iron in the sluggo product?

Last year, I tried several holistic methods and had success with a couple. They sell little tiny shot-glass sized plastic cups and I buried them to the rim and filled with beer. I bought beer and also made my own mash with yeast, water and honey. The store-bought beer worked pretty well but some plants were still being chewed off.

I tried surrounding the seedling stems with sand paper and that worked until it rained. The grit washed off the sand paper quickly.

I tried putting leaves from mint plants surrounding each seedling stem. I sprinkled garlic and cayenne pepper on the ground. Those 3 things did not work at all.

But placing pennies vertically around each stem worked 100%. The pennies placed horizontally worked too, until it rained and soil washed over the copper and the snails crossed the barrier. It took 3 or 4 pennies placed vertically in a square around each stem to ensure the seedling survived. My garden is 150 feet long and it will be annoying as all get out, but I will be planting pennies this year, along with each plant. I'll use Sluggo outside the garden, a couple feet away from the perimeter.

That's interesting that everyone has such a tough time with slugs! I should also mention, I start pretty much everything indoors until they have a couple sets of leaves, mostly because I find they are less attractive to pests at that stage. The worst insect pest I've had in my garden is climbing cutworms (yellow underwing moth caterpillars) but they only feed between February and late April. I actually used to think what I was seeing was slug/snail damage, until I went out one night with a flashlight.

If your bed is raised silkak you could try this: https://www.amazon.com/Copper-Conductive-Adhesive-1inch-12yards/dp/B018RDZ3HG/ref=pd_sbs_86_1?_encoding=UTF8&pd_rd_i=B018RDZ3HG&pd_rd_r=W8YS2XGXD3MS7CHJEKJ6&pd_rd_w=t5Hca&pd_rd_wg=dDePw&psc=1&refRID=W8YS2XGXD3MS7CHJEKJ6