Chappy from the marvellous xkcd.com shares this story:
“I’m at Sarah’s place, about to crash, and I just turned my head to the
right and there were a pair of EYES, set in the face of a strange cat
sitting on the back of the couch, literally an inch, an inch and a half
from my face, staring at me intently. I propose all animals with quiet
feet and eyes above a certain level of creepiness be fitted with bells
You know who else was fitted with bells?
The twin evils of the medieval age, lepers and jesters.