Snails not moving

[EmersonW]

Hey Everyone, i am a noob at aquariums and i just got four snails. Two of them seem to be happily moving around and eating but the other two are not moving. One of those two has a little opening where they are meant to come out and the other one is tightly closed.
Thanks

 

[JuiceBox52]

Wait a couple days to see if it moves. My nerite will stay in one spot for 4 days at a time. If It hasn't moved for a few days, smell it. Dead snails will give off a horrible horrible smell

 

[Derekshatch]

I accidently left my nerite in a bucket that I used for a water change and i found him and was still alive even without water.

 

[Colin_T]

make sure your water quality is good and there is no ammonia or nitrite and the pH is above 7.0.