Incidents of migrant children violently bullying their peers have aroused public concern, and experts warn that mental health is no less important than physical health as migrants adapt to city life.

"It is important to teach migrant children how to let out negative emotions in a proper way when their parents are too busy to lend an ear," said Su Pei, chairwoman of Guangzhou Women's Federation.

On May 23, three teenage boys — two 15-year-olds and one 17-year-old — assaulted another boy in Naixi village in Beijing's Chaoyang district, beating him severely. A video of the incident went viral on the Internet on May 25.

All the boys were the children of migrant workers.

"We have civil affairs administrations to provide relief to acutely ill children, but the attention to migrant children's mental health is still insufficient," Su said.

Children who chronically lack parental oversight for long periods are regarded as "actual orphans", meaning that their parents are alive, but ordinary parental care is not provided.

Part of the answer to the parenting gap may lie in better custody laws, according to Ja Ying, manager of the Shanghai office of Save the Children, an international charity organization based in the United Kingdom.

Ja said lawmakers should specify under what circumstances custody can be transferred to other parties — relatives or institutions, for example — for the good of the child and society.

The women's federation has taken another approach. To better serve the estimated 2 million migrant children who live in Guangzhou, the group designates a school as a "Home for Migrant Children". Seven local primary and middle schools were identified on May 29, and the federation's resources will be integrated to provide a full range of services to the disadvantaged group.

The package includes health care, family education, aid to acutely ill children, engaging children in community activities and building a system to prevent and deal with domestic violence.

Adult migrant workers tend to rely on schoolteachers to educate and supervise their children, which greatly increases the school's burden, Huang Xinmin, principal of Fanghua School in Guangzhou's Liwan district, said.

Almost all of the 1,800 students at the nine-year school are the children of migrant workers.

Although the morning reading session starts at 7:40 am, the school has to take in students starting at about 6 am every day because the parents are already on their way to work. The day stretches to 5:30 pm for the teachers who need to look after students until parents return.

"We try our best to teach students life skills and enrich their extracurricular life," Huang said, raising the school's free-of-charge brass band play group as an example.

"We also require our teachers to befriend the students and pay close attention to their mental health."

Luo Huanxin, a Chinese language teacher at Fanghua who is currently the school's only counselor, has more than 300 students on his QQ friend list, and he chats frequently.

"I feel like I am the parent of my students," Luo said.

In the daytime, he gives lessons and often needs to spend time settling conflicts between students. Upon returning home, he checks QQ chats first to see if a student is asking for help, and then starts preparations for the next day's lessons. Luo's monthly salary is between 2,000 and 3,000 yuan ($320-$480).

"The lack of communication between migrant workers and their children is a big problem," Luo said. "Students don't know how to ease negative emotions, and some will vent on schoolmates without knowing they are doing wrong."

Sometimes a child's frustration may be rooted in the gap in a migrant's living conditions compared with city children, according to Su of the women's federation.

The Guangzhou city government plans to establish a service center for children that will be staffed with social workers provide entertainment, education, psychological counseling and referral services in at least 90 percent of the local communities in 2020, officials said.