Black lights need to be used in the dark to be effective. To get an idea of what urine stains look like, point your light at your toilet bowel in the dark. The bright yellow stains are urine stains.
You should be able to see stains by holding the black light pet stain detector while standing looking at the floor in the dark.
Use caution when operating an LED black light pet stain detector. Never point directly in your eyes or into reflective surfaces such as mirrors. KEEP AWAY FROM CHILDREN! UV LED black light pet stain detectors are NOT TOYS.
