"Catscat"?  Really, Dad?
My dad has been gardening his whole life.  I think he found it relaxed him after a long day at work.  Most of the time he's had great success, though I do remember one shady front yard giving him grief as nothing would grow in it.  But when I visited him yesterday I noticed these plastic things in his garden that were square with spikes sticking out.  I gave him a quizzical look, and asked "cat problem?"  And he answered that "yes" the neighbor's cat was using his garden as a litter box.  I then asked, "and you don't think the cat is smart enough to go around?"  To which he pointed above the "catscat" row and said, "Apparently it is".

Pests can be a huge problem in any garden.  I also have a lot of neighborhood cats who think that any workable area is a litter box.  Since I have four cats (all indoors) I am quite patient and will even talk to my feline neighbors when I spot them in the yard.  When I see something that they've done left behind, I will pick it up with a small bag (like a doggy bag) and simply dispose of it.  Frankly, even if it did bother me it would take more than a few "catscat"s to surround my yard.  On the brighter side, because I am more urban, I do not have to worry about other would be pests that are a problem for gardens located on the more wooded side of town.  Such animals as deer and ground hogs will eat many types of plants.  In my last house in Massachusetts there was a family of ground hogs living under a neighbors' garage.  I do not think the neighbors minded or they would have relocated them.  Once in a while I would spot a ground hog in my garden and instead of running out and chasing it away, I would grab the camera and take photos.  So cute!

That said, there are humane methods to deter pests (such as "catscat" won't hurt a cat, it will just make them go around the plastic square to get where they want to be) or even better plant with wildlife in mind.  You can either plant flowers and shrubs that do not taste good to wildlife or plant shrubs and trees that produce berries and flowers that will actually provide food for them.  It's something to consider when in the planning stages of your yard.