Black lights are a real slippery term. True black lights and very bad for YOUR eyes. Your snake has a UV coating on their eyes, you don't (UVa + UVb blocking sunglasses...) if it is a UV bulb you should replace it with a blue one. Sometimes bulbs that are deep blue are called UV short of a meter it is hard to tell the packaging should let you know. If it makes glow in the dark stuff go crazy and shirts go that UV effect I personally would replace it. Deep blue is my choice , heat (IR) is only a few nM longer than deep red, pythons hunt with IR, deep red is close to the wavelengh they are 'tuned' for.