A Cat's Eye View - the baited trap

My entry for the latest Wide Angle Wednesday challenge - the Cat's Eye View. Many thanks to hobbs for doing whatever it is that is involved in hosting such a challenge.  Much appreciated.

I wasn't sure whether to make this a black and white shot. I seem to remember being told, as a child, that they say cats can only see in black and white. That prompted two questions for me:

1. Who are "they?" and
2. How do "they" know?

PS - by courtesy of a friend on another photo-sharing site - here are the answers.