This video from the USA says about itself:
Beneath the towering redwoods lives one of the most peculiar creatures in California: the banana slug. They’re coated with a liquid crystal ooze that solves many problems slugs face in the forest — and maybe some of our own.
Dutch magazine Natura, September 2015, page 3, describes that Ms Prinsen accidentally spilled breadcrumbs in her garden. The breading almost immediately attracted twenty slugs to feed on it.
This led to a way of removing slugs from gardens without killing them.
1. About sunset, scatter breading at various places in the garden.
2. Come back an hour later, and find lots of slugs there.
3. Put the slugs in a bucket and bring them to a place where they will be able to find food, but won’t harm gardens.