The Ancient Egyptians didn’t just mummify their dead human ancestors, they also mummified animals – in their millions. It’s possible up to 70 million animals were mummified and then buried in underground catacombs at over thirty sites across Egypt. At the Royal Manchester Children’s Hospital a team of radiographers and Egyptologists from the Centre for Biomedical Egyptology at Manchester Hospital have been using the latest medical imaging technology to scan hundreds of animal mummies, removed from Egypt during the 19th and 20th centuries. It’s the biggest survey of its kind in history. Over three nights in Autumn 2014, Horizon filmed around a dozen of these scans which have made the backbone for a documentary that tells the strange story of the bizarre role animals played in ancient Egyptian belief.