The biker gang, that was really just a bunch of high schoolers, seemed to refer to themselves as the Wild Bones. They were pretty excited to talk about it in front of Zain, talking about all of their accomplishments and how they had taken over a lot of schools.
However, Zain having never heard about them had put a slight damper on their mood, but he quickly explained that he was a university student, and that if he was still in high school, he was sure he would have known about the Wild Bones.
When the attack had started, it had actually happened while they were in school. According to them, the teachers were useless and unorganised and most of them had abandoned the place instantly to get in their cars and drive away.
At the time, it was because of the Wild Bones, who were originally a much bigger group, that they were able to protect a school. One of the hardest places to make sure it was clear of zombies.