Arion Ater or Arion Rufus, the "European" Slug selective breeding.

[Wiggles92]

Try a more natural setup; I bet that they might breed then.

 

[knifegill]

Yeah, there was no soil layer in my first effort, just moss and plants with a tiny soil dish. I'll try an actual layer of soil, maybe some live grass and bits of wood, etc. Perhaps I'll even use a light, so they have a better idea of when day is. Although, from observing them, they really don't care if it's day or night, as long as it's cold and wet...

 

[FishFreak95]

I tried something similar with garden snails. After 2 days, I realized I don't like snails lol.
Good luck with your project.

Sent from my SPH-D600 using MonsterAquariaNetwork App