Yes they do. My Adult apple snail was ripped apart by my red clawed crab. So based on my experience, I wouldn't mix them together.
Chela
yes
by rubbing their big claw on there body
No.
red clawed crabs eat best when no one is around or watching them (at night).
they start to chase each other and then claw each other
It will drasticly reduce their life they are semi aquatic needing both dry lanf and water
Hermit crabs usually , if not always, have one large claw and one smaller claw.
In most cases yes, unless they lost their claw due to stress or sickness
They dip their big claw in the water and drink the drops on the claw, they do that over and over again until they are full.
its called a pincer
Well, most hermit crabs do not come out during the day, or when they know you are watching them. to see if they are alive, carefully put your fingewr nail on there claw, or blow on them. If they move it, than they are ok. If it is very stiff, they are still ok. If you can move there claw, yourself, and it is very wiggly, they are not usually alive.