Heihaizi

Heihaizi or "black children" is a term applied in China, denoting children born outside the One child policy, or generally children who are not registered in the national household registration system. In Japanese the term becomes heihaizu (黒核子) or へいはいず (literally: "black seed child").

If a family that is not allowed to have another child according to the policy, does give birth to one, then apart from the financial and social penalties resulting from the disregard for the law, the second child is not entered in the family register and lives their whole life as so. Never entered in the family register, they do not legally exist, and as such, they are unable to access most public services, such as education and heath care. They also are not able to be hired in a job or any activity that requires identification or verifiable registration. Apart from illegal activities, such as crime or mafia, they can either help their family in agriculture (in rural areas), or in case of girls sell their body.

In some parts of China, children are conceived and born only to be sold to smugglers, usually hours after birth, who then sell them either to wealthier families inside China, or smuggle them abroad for the same reason. They may also end up working in factories, while pretty girls can be sold to underage brothels or as child brides.

In the 2000 Chinese census report, the number of persons not registering was up to 8,052,484, amounting to 0.65% of the total population.

Due to the aforementioned policy and the preference of male heirs over female ones in families allowed only one child, if the woman becomes pregnant with a daughter, she sometimes gives birth to her in secret and chooses not register her, so that later on she can try to have a son, and register him instead.