Conservation is responsible for the long-term preservation of the collections, and covers all the collections held by the V&A and the V&A Museum of Childhood. The conservators specialise in particular areas of conservation. Areas covered by conservator's work include "preventive" conservation this includes: performing surveys, assessments and providing advice on the handling of items, correct packaging, mounting and handling procedures during movement and display to reduce risk of damaging objects. Activities include controlling the museum environment (for example, temperature and light) and preventing pests (primarily insects) from damaging artefacts. The other major category is "interventive" conservation, this includes: cleaning and reintegration to strengthen fragile objects, reveal original surface decoration, and restore shape. Interventive treatment makes an object more stable, but also more attractive and comprehensible to the viewer. It is usually undertaken on items that are to go on public display.