strange reaction to substrate change

[steph9]

I started my baby california king on cocofiber bedding for the first month and recently changed it out for aspen snake bedding. Since the change four days ago, I haven't seen her. The tank lid is secured with clips so I'm confident she didn't escape. She used to be very active during the day and evenings, so I'm not sure what's going on. I left a pinkie mouse in her enclosure overnight and she didn't come out for that either. I'm worried she died from the stress of getting new substrate, because she isn't even coming out at night. Any suggestions?