Nor I, but let's see if it passes the Cleon Test (TM).  
		 
		
	 
I don't like this bit:
"An infested creature takes 2d4 points of Constitution damage per round,  plus an additional 2d4 points of Constitution damage for each failed  Reflex save against a crystal nipper swarm's attack. A successful DC 16  Fortitude save halves this damage."
That means if they fail the first Reflex save they take 4d4 Con damage per round, which is more than the 2d4 we were going for. If they fail three Reflex saves they'll take 8d4 Con damage per round, halved with a save - few living creatures would last very long with that amount of damage!
My initial thinking was something like "An infested creature takes 2d4 points of Constitution damage per round, a successful DC 16  Fortitude save halves this damage."
However, I like the idea of the damage increasing as they fail saves and get infested by more and more nippers.
How about the following (I corrected two mispelled "resurrection" and modified the "raise dead" bit a trifle):
Infestation (Ex): Any living creature that takes damage from a crystal  nipper swarm might also be infested with crystal nippers each round. A  creature must make a successful DC 18 Reflex save to dodge the swarming  nippers or bat them aside. The crystal nipper infesting the creature  burrow into its flesh. 
An infested creature takes 1d4 points of Constitution damage per round,  plus an additional 1d4 points of Constitution damage for each failed  Reflex save against a crystal nipper swarm's attack. A successful DC 16  Fortitude save halves this damage.  After 2d4 rounds, the sated crystal nippers crawl or swim away. A  crystal nipper infestation can be removed with a successful DC 20 Heal  check, though this check (whether successful or not) deals 1d6 points of  damage to the infested target. Alternatively, a crystal nipper  infestation can be destroyed by 
remove disease or any other effect that  halts or counters a disease. Such spells destroy all the crystal nippers  inhabiting a target.
 
Medium or larger creatures that die from crystal nipper infestation  spawn a new crystal nipper swarm within 2d4 days. Burning or otherwise  destroying the body prevents this. Casting 
raise dead to restore a  creature killed by a crystal nipper swarm 
but this does not destroy the crystal  nippers 
infestation, casting 
remove disease or a similar spell in the  round afterward removes the nippers normally. 
Resurrection and 
true  resurrection destroy the crystal nipper when cast.
Oh, and should we add "The Reflex save is Dex-based, the Fort save is Con-based." or can we safely leave that unstated?