Snail breeding attempts

[Sombat]

I just had a thought on trying to identify the male and female mystery snails I have in my tank. I have not had any luck getting the snails to come out of the shell well enough to sex the snail. I read and have seen some videos that state only male snails will mount another snail even if that snail is also male. Please correct me if that’s wrong. If that’s true, a female will never mount another. That being said, I was thinking I could use a permanent marker pen and write a “1” or some other small mark on snails I observed mounting another until all 6 of my snails in the tank are identified. Please give me your thoughts on marking the shells. If you have a better idea please share. Keep in mind I have not marked any snail at this time. 

[xXInkedPhoenixX]

Honestly, just watch them. It's pretty obvious who is male and who is not after a while. I have 1 male and 2 females. He's constantly on them.