Floating?

Question
HI!
I have a gold mystery snail.
Today it floated up to the top of the water and it was hiding in it's shell at the same time but it is still alive!
Also it did the same thing but this time it was sucked up by filter, the sucking water part. The flilter did not suck the snail. in side the filter.
Why did floating happen?
It lives in a 5.5 gallon tank with filter, heater, and light.
Sam

Answer
Hi There,

Well,  snails can be very inactive for days and if they have a lot of air in their lung, they float. Floating of a  snail doesn't indicate that there is something wrong or that he/she is dead.
To check if the snail is alive, take it out of the water and see if you can get it moving by touching the shell door. If the shell is closed completely, then you can be sure that the snail is alive because once the snail is dead, the muscles are relaxed and the shell door stays at least partly open.
Another way to check the snails is by looking at the heartbeat (only possible with young snails and snails with a thin shell). To do this, keep the snail in front of a strong light source so the light shines through it and look at the heartbeat.

Hope this helps,
Chloe :)