Kidnappers have seized more than a thousand students and staff from schools in a series of raids across northern Nigeria. The wave of abductions has devastating consequences for the country, which already has the highest number of children out of education anywhere in the world. Parents face extortionate demands in exchange for the freedom of their sons and daughters, and many families in Africa's most populous nation are now too afraid to send their children to class. Mayeni Jones travels across north-western Nigeria to meet those affected and find out what's fuelling Nigeria's kidnap crisis.