In this paper we use data from the 1% British Household Sample of Anonymised Records (SAR) to examine coresident households which have been formed by the movement of people under the age of sixty five into the homes of elderly people. The SAR does not give information on why such moves have taken place. However, an examination of the characteristics of the movers and their elderly receivers, and the relationships between the two, sheds some light on the issue. Analysis shows that most movement into the homes of elderly people is by people who are related to them -- mainly their children and their children's partners and/or children. It is often assumed that coresidence between elderly people and their younger relatives is driven by the care needs of the older generation. However, in this paper we cast doubt on this simple assumption, arguing that it is equally necessary to look at the characteristics and circumstances of movers in order to understand coresidence in the elderly households under examination.