They want to sell you a product. Period. Think about the natural habitat for a ball python... old termite mounds or animal burrows. No lights in there. Most pet stores and many online articles will say that ball pythons also need heat lamps and/or basking lights, but it has been proven that they just as happy and healthy, if not moreso, without those things. If you have your bp enclosures someplace with no windows, so no moonlight/streetlights, etc can get in, then maybe a nightlight in the room would be okay, but I still wouldn't fool with putting a light in their enclosure for nights.