When I first got Caspian, I was house-sharing with a friend, J in a house which had a dark brown, speckled stair carpet on a narrow staircase which had two bends and no separate light and no window. J also had a cat -- Rhani -- a dark tortie tabby who was only just out of kitten age. Caspian and Rhani were bestest friends and spent all their time chasing each other, playing hide and seek and so on.
One of their favourite games went like this.
It is any time after twilight -- preferably very early morning. Caspian sits on one of the least well-lit stairs and lurks. A human gets up and blunders downstairs in the gloom. Halfway down, they just about make out the shape of a dark grey cat on the stair and step over than step... straight onto Rhani, who was the exact same shade as the carpet. Rhani shrieks, human tumbles down the stairs, other humans wake up complaining, cats get guilt offering of chicken, cats repeat the game...