Bed bugs have been sucking human blood for thousands of years and they’re enjoying a new resurgence. They are among the most difficult pests to control, and infestations have risen in the last few decades. Old defences like insecticides are failing us, leaving scientists racing to find new solutions. But in the Balkan countries of southeastern Europe, there’s a old folk remedy that might be the insects’ undoing.

Before nightfall, people would scatter the leaves of bean plants on the floor by their beds. In the morning, the leaves would be full of immobilised bed bugs, which could then be taken outside and burned.

In 1944, a scientist called H. H. Richardson realised that this works because of tiny hooked hairs