What Did I need to Know Before I Purchased My Nass (Nassarius vibex) Snails?

[Enigma]

I did loads of reading before I purchased my Nass snails. They sounded like the perfect snail for my CUC. But, they aren't the peaceful little sandbed cleaners that I was expecting.

Holy smokes these things are aggressive! I have no reason to believe that they're predatory, but they certainly aren't peaceful. They chase each other. They wrestle with each other. Sometimes it is so bad I feel as if I need to pull them apart. It kind of freaks me out. I had 9, but now I'm down to 8 (one was dead and mostly eaten this morning).

Also, they aren't great sandbed cleaners. I thought they'd clean up after my two small Mexican Turbos (who generate a HUGE mess). Nope. They don't seem to eat poop. They don't eat seaweed. The do seem to eat the frozen brine shrimp that my Chromis don't get to. I'm pretty sure these things are carnivores and not omnivores. They do really stir up the sandbed, but I wouldn't say that they "clean" it.

I'm sure they're not Welks (I've spent a couple of hours going over photos and examining them), but these Nassarius vibex sure aren't what I was expecting.

Is there anything else that I haven't figured out about them yet, which varies from the common perception (especially this: http://www.liveaquaria.com/product/p...3&pcatid=1133)?