For "Cat" fishing, try this. Take the hook out of a Snag-Proof brand mouse lure. Run your line through its nose and out where the hook usually sits. Then pinch 2 or 3 split shot on the line.
The shot should be just small enough to pull back inside with a tug.
I "fish" this on a fairly light rod with fairly heavy line (Light to med. freshwater bass rod w/ 40# test line). This way if my cats or kids get hung-up the rod doesn't have enough power to hurt them and the heavy line doesn't dig into the skin.
My 2yr old son thinks it's a blast to try to catch the mouse before the cat can. Of course the cat always beats him, I make sure of that.