An inaccurate and misleading statement.
At my property I do battle with field mice who are trying to setup house in my garage while at the same time the space under my three-season porch reeks of cat urine. The well-fed neighbor's cat doesn't bother with the mice, but it still needs to relieve itself somewhere
But why under my porch? :(
Perhaps the cats feel your antagonism towards them...they do things like that, you know.
I'll bet that you have nice, soft, easily dig-able dirt under there.