In the limited (but probably dominant, here at HN) context of middle-class-ish urban dwellers, I daresay there would be a sizeable proportion of clean, well-sea

In the limited (but probably dominant, here at HN) context of middle-class-ish urban dwellers, I daresay there would be a sizeable proportion of clean, well-sealed modern homes in which rat ingress is at, or almost, zero. Doubtless there is also a significant proportion of homes where rat ingress is more common. But I couldn't begin to speculate about where those numbers might actually fall.