At shops across the country, some of the most popular sales associates have four legs, twitchy ears and whiskers.

If you're new to the Cat Rating System (CRS), never fear—it's pretty easy to get the hang of. All you have to do is rate your cat's characteristics on a scale from 1-10.

The cats don't always understand the human specifics, but they recognise sadness. They notice routines. And most of all, they ...