Snails disappearing?

[MadSkillzMan]

hi guys...sorry i havent been around in forever, been really busy

anyway i HAD 2 of those larger snails, they have a silver/white center in their shell, but a dark brownsh/black (now purple) tint..anyway the big things that suck all the algae off ..i had one fall to the bottom of the tank, and by the time i foudn him, the snail was missing from inside

ooook fine..i figured my hermit crab got him

So some weeks went by, and another snail turned up..this one i didnt buy/recognize this one but fine

So last night i find my other little black/brown snail laying at the bottom..he fell off a rock..so i put him back on...today, hes not in his shell...i put the sehll back on the rock, incase hes really in there..and i notice onea my other snails (a white one) is sitting on the LR, with tentacles wrapped all around him...probably starfish ron gave me...

my question is, where the heck are they going? i mean if they died theyd still be in there

All i have is hermit crab, a clown (nemo) a tomato clown, white snail, and a bumble bee snail somewhere beneath the sand

thanks in advance!

 

[ScarabIII]

I have that problem too with snails, everythin else is healthy, water test good, but cant keep any snails.