Hehe, I had this problem with Ginger (no snarling, just sqirming and nipping). I asked at one of our puppy training sessions, and the trainer got one of the collars that snaps on instead of buckles and I held her so she couldn't run while the trainer put it on and off about twenty-five times in a row. Then we let Ginger run around a little and did it again about twenty-five times. Just that one session worked. She was no longer nervous when I put her collar on.