like i said earlier, im only going off what ive read in these forums. when purchasing snails, i was told not to purchase bumble bee snails. so i dont know off first hand, it should be fine though.
They eat other snails. (a type of welk which hunts down snails and eat them.)
However i have never found this. I guess it might be simply because it had plenty of easy food to eat.. if there were scarce food then perhaps its predatory instincts would kick in.
I also have about ten bumbble bee snails in my tank with no issues. One even made it down the overflow and into my wet/dry where it has lived off detrius for about three months now.