White String (worm?) On Zebra Snail! Help

I got my first ever nerite snail two days ago and this morning I saw this on my snail (see pictures). The white thing is not moving, it and the snail have been exactly as pictured for the last half hour. The tank has 1 live plant, 3 moss balls, 3 ghost shrimp, and now this snail. What is this? Do I need to be concerned? Is it a worm?

 

Does it move?

If so, it could be a parasite. I just think it’s poop.

 

I did eventually see it move, but I was able to grab it with tweezers and get it out of the tank. Unfortunately, I think the snail died overnight. I found it upside down and half hanging out of its shell this morning. It wouldn't move when I touched it and it smelled pretty bad when I took it out of the water. I think I will stick with the ghost shrimp and plants moving forward.

 

Dont get discouraged it was just probably already sick from where you got it from i have 5 nerite snails in total and a mystery snail living with a colony of yellow shrimps, one thing i always do before picking one out from store is making sure its active and either on the glass or some decor.