According to new research, house mice (Mus musculus) are ideal biomarkers of Human settlement as they tend to stow away in crates or on ships that end up going where people go. Using mice as a proxy for human movement can add to what is already known through Archaeological data and answer important questions in areas where there is a lack of artefacts, Searle said. Where people go, so do mice, often stowing away in carts of hay or on ships.

Despite a natural range of just 100 meters (109 yards) and an evolutionary base near Pakistan, the house mouse has managed to colonise every continent, which makes it a useful tool for researchers like Searle. Previous research conducted by Searle at the University of York supported the theory that Australian mice originated in the British Isles and probably came over with convicts shipped there to colonise the continent in the late 18th and 19th centuries. In the Viking study, he and his fellow researchers in Iceland, Denmark and Sweden took it a step further, using ancient mouse DNA collected from archaeological sites dating from the 10th to 12th centuries, as well as modern mice. He is hoping to do just that in his next project, which involves tracking the migration of Mice and other species, including plants, across the Indian Ocean, from South Asia to East Africa.