worms... (not bristle)

so in my new tank ive been noticing at night there are a few worms roaming the rock work and never ssen or heard of them before. They arent bristle or fire worms but look more like a regular old night crawler. They are brownish tan and literally look just like a bait worm or night crawler... There are alos those little mini snails that only come out at night which I have in both tanks and wondered of those are pests of pets???  anybody ever heard of or saw these fellas???

 

What about those little snails that creep out at night? Are those bad? The have little flat shells almost and are really small. I've heard ppl talk about em but don't remember if they are a pest or ok???