You can spray them with bt (can't remember exactly what its real name is, something like bacillus theren-something-or-other-um.)

If they're doing all right in their current location, I would prepare the new area & let it age, but wait until a killing frost "melts" the foliage (or at least until they go dormant, however that happens in your area!)to dig the rhizomes & move them then, when they're "asleep".

I've had the best luck moving things when they're asleep.

When they wake up, they don't even realize they've moved!