On the outskirts of a town called Fatick in Senegal , I was squatting in a hut with two middle-aged men, both traditional healers. One of them was explaining to me in sober tones how he first came to be a healer, and the social responsibilities that come with being the custodian of the knowledge of his forefathers. A few yards away, more healers were gathered together, having travelled miles by cart and horse. This is the headquarters of Malengo, a network of traditional healers working across the country. It is just one of the many such networks that have sprung up around Africa , and it is driven by the need to preserve, share and recognise the importance of indigenous knowledge.