I have to share my story that's kind of related to this!
So Scully is gravid with her second clutch. She's been digging for the past 5 days or so. She also had her front right arm amputated on the 24th of Feb. So I set up a Skype account to spy on her whenever I want during the day, since I can't let her be out while hubby and I are at work.
This Friday, hubby and I had plans and he had to leave right after he got home from work, which is just a few minutes before I leave my work. So I was Skype-spying Scully, she was just kind of hanging out on her basking spot. I heard the noise of the laundry room/garage door opening and my hubby's voice. Scully heard him too, and the moment she heard the commotion, she cocked her head, listening until she heard hubby's voice (talking to our dog in the other room), then she immediately started making digging motions. She paused when the noise died down (hubby letting the dog outside), but as soon as she heard him again, started digging again! Then a few seconds later I saw his hand come in the tank and lift her up so he could put her in the lay bin.
I had never seen anything like that before - basically Scully identifying our voices, knowing that we would be the ones to take her out of her tank so she could dig. It was really cool to see!