Is there a rat problem in Neath?

There is a worrying article from the US capital. One paragraph stands out:

 I found that not only is it pretty easy for a rat to climb up a three-inch toilet drain pipe (most of the time there’s not even water in it), but I live in a part of D.C. with a combined sewer system, so the storm drains on the street and the pipes from the toilets run to the same place. A combined sewer is one big, happy, Rat Central Station. 

I do not suppose that American rats are any smarter than Welsh ones, and most of the old industrial centres of south Wales, thrown up in a hurry during the Industrial Revolution, have antiquated drains.