There is no reason to connect the slug eggs to the mulch other than chance!
Hosta collectors are obsessive compulsive given to fits of uncontrolled fits of euphoria and fear, that's why daylily collectors make fun of us.

Are slug egg clusters the size of quarters???

They look like timed release fertilizer pellets.

I haven't done it but surely someone has applied ammonia to slug eggs see what happens.

I had lots of mulch delivered here last year. No slugs, or eggs, that I could see. Lots of of grubs, though. I just put it down anyway. No problems this year.

you said the pile has eggs ...???

that surprises me... as i thought slugs preferred vegetation over wood????

are you sure they are slug eggs???

ken

Slugs love wet wood. I'm finding fat juicy slugs under every board/trap I turn over. No slug eggs tho', I have hardwood mulch everywhere.

Slugs lay eggs and live near their source of food, what would be nearer your plants than the mulch. They will be under whatever they can find and will crawl away during the day and crawl back at night.

Mulch has nothing to do with it!

Don't we all?

When do slugs actually lay their eggs? Maybe from now till the next 10 days I should open a nice juicy fat slugs to see if it has any eggs inside?...

Papou

Maybe those fat ones out there now do contain eggs .......

From OSU Bulletin:

Though slug eggs may be found outdoors during any month of the year, most of the eggs are laid in the spring and early summer. Most species overwinter as adults or nearly mature young. In the spring, eggs are laid in moist areas and the new slugs normally reach maturity by fall. During periods of particularly warm and wet climatic conditions, the rate at which the slugs develop may allow for eggs to be laid in mid-summer, thus making possible a second generation. Mating usually takes place from August until mid-October and eggs can be laid from 30 to 40 days after a successful mating.

Eggs are generally laid on or near the soil surface, but are usually deposited in places of concealment, such as underneath mulch, dead leaves, rocks, flower pots, trash, and boards. Particularly preferred are spots where the nature of the cover keeps the surroundings relatively cool and moist.

The minimum temperature at which egg development will take place varies with the species of slug but is in the general range of 32 to 42 degrees F. At the minimum temperature, as long as 100 days may be required for the eggs to develop. At higher temperatures, development is usually completed in ten days to three weeks.