Why they call it like this .....
Because you will use it exactly like how the cat use it...... check this video below
It's a ladder used for working on a sloping roof, with a hook at one end and pads to spread the load.
Cat ladders are delightful contraptions that usually affix the the outside of a house or apartment building, providing a cat with easy access to the outdoors from a home that’s several stories up.
This interesting cat ladder is built with small ledges enabling the cat to go from one to the other, but the tabby prefers to scamper straight up the middle, climbing the ladder. This well-trained cat comes when he’s call and climbs the ladder on command.
Why they call it Cat Ladder check video below.....