dont quote me on this, but im pretty sure that snkes can sense the light. If you buy a "Night Glow" from a pet store, whcih basically is just a black light, it says on the back..... Creates a Night time atmoshpere for you snake, so i guess they can, i know when i turn off my floresent and just my black light comes on, chong comes out and becomes VERY active, climbing the trees trying to get near the light and digging under the substrate, just havin a good time