And we can someone split on wall and splill on walls from milk or coke etc but when without uv blacklight we cant see super little uv light which is quite brighthave used this light for inspection of basement walls and floors for signs of water seepage and repairsinteresting to see the difference you can see when minor touch ups have been done in home repairs due to the different reflectivity of materials such as caulking and especially different paints that seem invisible in normal lightkids also like the light for charging glow in the dark materials and just having fun works great very handy i have taken this gadget on my travels and it