For the past couple of years, I've been working with researchers in northern Greece who are farming metal. They are experimenting with a trio of shrubs known to scientists as "hyperaccumulators": plants which have evolved the capacity to thrive in naturally metal-rich soils that are toxic to most other kinds of life. They do this by drawing the metal out of the ground and storing it in their leaves and stems, where it can be harvested like any other crop. As well as providing a source for rare metals in this case nickel, although hyperaccumulators have been found for zinc, aluminium, cadmium and many other metals, including gold " these plants actively benefit the earth by remediating the soil, making it suitable for growing other crops, and by sequestering carbon in their roots. Hyperaccumulators are far from being the only non-humans that we might learn from. Physarum polycephalum, a particularly lively slime mould, can solve the "travelling salesman" problem " a test for finding the shortest route between multiple cities " faster and more efficiently than any supercomputer humans have devised. Spiders store information in their webs, using them as a kind of extended cognition: a mind outside the body entirely. A new conception of intelligence is emerging from scientific research: rather than human intelligence being unique or the peak of some graduated curve, there appear to be many different kinds of intelligence with their own strengths, competencies and suitabilities.