What's up with my nerite?

[Fishyk80]

He has been half in/ half out of his shell for several hours. Earlier he was like this but moving his antennae around and looking like he was deciding whether to open up or not. When I got kinda close to the tank he flinched, so I figured I should leave him alone and he'd be fine. But just now I checked on him and was surprised to see he hadn't moved yet. He's several years old- either 2 or 4 years old (I have two that look alike that I got at different times).

 

[StarGirl]

Nerites only live a few years so I would say if it is like this tomorrow....

 

[Fishyk80]

Nerites only live a few years so I would say if it is like this tomorrow....

Thanks

 

[StarGirl]

I would try to flip him right side up though. Forgot that....They can't do it themselves sometimes.

 

[Fishyk80]

The snail isn't upside down. Earlier I saw him upside down so I turned him over close to the side of the glass so he'd have something solid to grab onto, and I'd be able to monitor what he's doing.