A Scottish executive strategy for foster care, due next month, must set local authorities clearer targets for the quality of care, according to one expert.
Barbara Hudson, director of the British Association for Adoption and Fostering Scotland, said the strategy ought to look at whether there should be a maximum number of moves for foster children.
It should also consider whether a limit on the number of fostered children in a single household would be effective, she added.
Hudson said the executive must look at whether councils were striking the right balance between preventive work and emergency intervention.
She added: "Children are coming into care in an emergency but that means they move around a lot."