A Hive of Activity Today the only permanent residents on St Kilda are the staff who service the Ministry of Defence installations. In the summer months, however, St Kilda is a hive of activity. A unique outdoor laboratory where architects, archaeologists, natural scientists and historians study the St Kildan way of life and the natural environment of the islands. These studies are fascinating in themselves and highly relevant to the long term care and understanding of our planet. Human History The history of human settlement on St Kilda is a complex and fascinating one. On the islands themselves are numerous archaeological sites, and remains of houses and other structures, which hold many clues to the way of life of the islands' former inhabitants. These are scheduled under the Ancient Monuments and Archaeological Areas Act, 1979 and may not be investigated or disturbed without the consent of the Secretary of State for Scotland. Natural History There has been a great interest in the natural history of St Kilda, since the middle of the 19th century. This continues today under the supervision of Scottish Natural Heritage. A research project studying the Soay sheep begun in the 1950s continues today and there have been major surveys of the seabirds on and around the islands.