Why do cockroaches show up even in clean places?

The short answer

Climate and urban density, not hygiene. The medina's interconnected drainage and shared walls create pathways between buildings. A cockroach in a clean riad travelled from the infrastructure below.

Marrakech's medina is one of the densest urban environments on Earth — roughly 30,000 people per square kilometre. Buildings share walls. Drainage channels connect entire neighbourhoods underground.

Periplaneta americana thrives between 25°C and 33°C, which describes Marrakech for seven months of the year. It can flatten its body to fit through a gap the width of two coins.

A single riad can spray, seal, and sanitise — and the roaches return through the shared drain from the building next door. Effective control requires every building on the same drainage line to treat simultaneously. In a medina where some buildings are abandoned and some owners live in Casablanca, coordination is impossible.