Comment by jghn

Anecdata but feral cats can help in the sense that the rats go elsewhere. I live in an area with a thriving rat population. There used to be a feral cat colony next door to us. In those days we almost never saw signs of rat activity, but our friends at the other end of the street were inundated with them. Construction happened, the cats were removed, and now both ends of the street have roughly the same level of activity.