1) How do scorpions know when its dark out if they're in a cage all day and night? its usually dark in my room but still my scorpion only comes out at night.

2)What would happen if i put a lightning bug in the cage and let the scorpion sting and eat it, would the glow stuff be visible on the scorpion?

1) My guess is internal clocks present in many, if not most / all multicellular organisms. It's also generally darker at night and there is less activity, so your scorpion may be more comfortable wandering around at those times.

2) Not many adult beetles make good feeders (most have repugnant chemicals), so I'm not sure if your scorpion would eat in in the first place. If they did, however, the bioluminescent chemicals may very well be visible on the mouthparts.

The internal clock on a scorpion is incredible but given enough time you can actully confuse them but there are so many factors that are involved.
1. light they can sense light with eyes and it is believed their tails as well. (i dont know how...yet)
2. Temp
3. Humidity
4. other noctornal animals triggering theirs sensors.

i was thinking it was something internal. would light from a digital camera stress them out at all? ive been trying to get more and better pics so it can be identified already but i figured constant flashing bright lights couldnt be too good for it. i just tried taking one with my phone and when the flash went off it freaked out and hid. the light from the digital camera never scared it before

I'm pretty sure lightning bugs are poisonous...

lightning bugs are poisonous well i know they are to bearded dragons, i dunno if a scorpion could handle it or what

well it's said they have light receptors in thier tails, and its probably an instinctive thing too.