I have two questions:

1. Are slugs a good food source for garters? I've read that they are, but rarely hear of them being used... I have a lot of them in my yard. A LOT.

2. I've read ALOT of things (especially on this forum) about how you can't feed snakes stuff from the wild because of parasites. I totally agree, but... I've also seen people from this forum talk about how they dig up there own worms (and slugs occasionally)... Is that safe? Do you recommend? If so, why are worms safe from the wild, but nothing else? Is it because of what they eat? This goes for slugs too.
I'm mostly asking because worms kinda expensive where I get them (PetsMart/PetCo) and I use them up quickly. And like I've said before THE ONLY local pet stores I have are PetsMart and PetCo. I hate those. They are expensive and take horrible care of their animals (petco is worse)... So I'd like to be able to dig up my own food... my own snake food, that is.