natural

Recently someone showed me a Facebook post from one of the piggy pages where someone had used a tray full of pebbles and such. Apparently they use it like a litter tray and it's natural enrichment for them? So I was curious if it was actually beneficial. Has anyone ever heard/done this?

I've been doing a lot of research into the piggies diet as I'm a new mum, and I want to keep it as fresh and organic as possible for him. Trouble is, the Internet doesn't have a great list of what common European plants and weeds are safe for piggies I have a large meadow behind my house that is...