Purring gerbils ques.

[Lauren Bowman]

Hello list!  Another probablt stupid question, but when i hold one of my gerbils, Molly, she "purrs" and trembles.  It it said to be a sign of love.   I find when she does purr, sometimes she grinds her teeth.  Is this a sign of dicomfort, comfort, or just gnawing down the teeth?  :) -Lauren