There were few things that scared me as a child — darkness and cockroaches were two of them. As I studied biology and later, had my first lessons in evolution, I realised that when cockroaches approach an area, the two factors they check are — how dark is it out there and the presence of other cockroaches. My juvenile fears found some scientific validity.

Now, you will wonder, in an urban wildlife column, why would I allow cockroaches in from under the door. But these nocturnal scavengers have been sitting tight in the dark recesses of the Earth for well over 350 million years. They have probably, with excitement, watched the Pangaea break and merge into today’s continents; delighted on the arrival of relatives such as termites and mantis; twinkled their compound eyes with 2,000 lenses when dinosaurs arrived and went extinct; and simply chilled through the many ice-ages that have ravaged the planet. And when humans arrived on the scene, they rightfully claimed their position and moved into our homes when we began to behave civilised.