Mutual Benefit Poem by Ima Ryma

Human domestication by
The what would become household cat,
Is probably thanks to rats - why?
Cats are drawn where rodents are at,
As a good source for food and fun.
As humans left the caves to farm,
A lot of rat damage was done
To the grown grains. To stop this harm,
The humans and cats struck a deal.
The cats would rats exterminate,
In return for steady home meal,
A purrfect match this did create.

A scratching backs concept of yore.
Of course cats scratch human backs more.