How nice of you to make a new potty for your kitties!*** :shock:There are several things you can do to keep the cats out.** Pine cones placed on top of the mulch will stop them, citrus peels like grapefruit or lemon placed on top, thorny plant clippings, a tea spray around the perimeter made from rue will keep them away, sweet gum seed balls placed on top or place chicken wire just under the mulch.* A more expensive solution for long term problems with many different critters, including deer, is a motion activated water sprinkler called the scarecrow.* You don't have to put the yellow face stickers on if you don't like the look.* They are about $75 to $80+.
There is also something called cat scat (not to be confused with the indoor scat mat) with sharp points that stick up.
I've also read that people stick plastic forks or knives into the soil like the spikes on the cat scat.
Backyardgardener, I couldn't get the link to work.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.