Where Are These Slugs Getting These Fucking Shells?

There's not a people like going to the store buying a big bag of empty little shells and dumping them all over the place. I remember learning that like hermit crabs and stuff will like if they get too big they will get a bigger shell, then another hermit crab will come along who has smaller shell but it's big for it. The slug is naked and it looks like he's trying to be salacious a little bit whereas a snail slug yeah the name slug is bad but it's got a right in thereIt's got a great in there and I honestly the slug I feel like there's just more touchable surface on it that I don't want  and a snail