DNA has been isolated from footprints left in the snow by three otters in Northern Sweden. Scientists at AquaBiota in Stockholm, Sweden, managed to retrieve large amounts of high quality DNA from snow footprints by using a new molecular technique. The results revealed both DNA from the otters themselves and traces from their latest food items which included brown trout, toads and common frogs. The non-intrusive method enables monitoring of individual otters, their movements and population structure, without having to encounter the animals or finding excrements. Genetic analyses to identify the different individuals are underway.