Whats up with my snail

[CanadianWaters]

I've had 2 mystery (?) snails for about a month and they have been super active and a way more fun than I predicted. One of them is now just not moving and I'm worried he's dead.
I've read that they will sometimes do this for a few days but I am still worried. I touched him gently and he didn't even respond. Even if he is taking a couple days rest or whatever it is he should have responded right? He doesn't stink what so ever but he has some white stuff coming out his shell.

 

[Foxtrot90]

Pick him up and gently shake him in the water, a dead snail will often just fall out of the shell (but be careful not to make a mess though)

If he seems ok otherwise just give him some more time. My snails will sometimes look almost dead for a few days before perking up again

 

[wildroseofky]

The white stuff sounds like snail slime. They will make this if something in the water is hurting them. Check your PH, ammonia, nitrite, and nitrate and do a water change. When they die they hang out of the shell. If it is still closed up then it is alive. They go dormant for days sometimes. If you water is fine than it is probably just taking a rest.