I think it's dying?

[leenie]

I think I got a dying snail here. He has been in the same position all day. He's pushed up against the glass on the bottom on the sand, but only part of him is suctioned. And if I look real close, I can see tiny almost microscopic white tadpole like things swimming around him... every now and then he will fully suck the glass and his head will poke out. I tried to move him with the net, but he sucked the glass harder...
Is he dying? And what are those tiny things swimming around him?
:notsure:
Thanks guys!