Russian officials have taken a five-year-old Siberian girl into care, saying that she had apparently been "brought up" by cats and dogs.
The girl, who is unable to speak, was discovered living in a squalid flat in the Siberian city of Chita.
Police said she had never been allowed outside and had adopted the behaviour of the animals she lived with.
They said she now "barked like a little dog" and jumped at the door when her carers left the room.
Police are questioning the girl's mother, but her father has not yet been found.
A police statement said the girl was unwashed, dressed in filthy clothes and had the "clear attributes of an animal".
"For five years, the girl was 'brought up' by several dogs and cats and had never been outside," the statement said.
The police said the girl had managed to master "animal language only", but seemed able to understand Russian.
Earlier this year, President Dmitry Medvedev called for more action on child abuse.
He said 750,000 children in Russia were living in "socially hazardous conditions".