I've heard that they like noise! My husband has to have the TV blaring everytime he watches it or is playing video games and my hatcher is right near the TV.....they always seem to start hatching when he turns it on! lol Try putting a radio or something that makes noise near them....
I wouldn't leave the light on though....could interfere with them resting, it takes alot of strength to get out of those shells so they will take frequent breaks! I've had some that have pipped and taken 24 hours to be completely out of the shell!