If you’ve ever wondered why your cat can walk around in the dark but still can’t get out of the way when you’re trying to walk around it, there may be a simple explanation for the ability of cats to see in the dark. (Nobody has an explanation why cats trip people up by walking between their legs and then wondering why they get stepped on.)

Apparently cats can see ultraviolet light, which humans cannot. Scientists speculate this allows cats to see urine trails, which can be handy for hunting down prey or just finding an unmarked part of the house to spray.

The next time you catch your cat staring off into the night, it could be seeing in the dark, or it could just be spacing out and getting high on catnip.

To read more about the ability of cats to see ultraviolet light, click here.