my 2 year old labrador is biting kids on bikes

Question
hi, my 2 yr. old lab named Aaron is bitting kids on bikes for some reason and he has bitten a kid who was walking aswell. he started dong this months ago but i thought that he hated people on mobile devices, but when he bit the kid walking, i got worried. he also doesn't come when i call him, he only behaves on the leash. if you can tell me what to do, id really appreciate. People told me i should put him down, but i really don't want to do that. please respond ASAP Before he bites someone else.

Answer
What kind of formal obedience training have you done with the dog?  I find that many folks who have such problems with their dogs have never really trained their dogs to obey them.  Formal obedience will also help you with teaching the dog to behave when off leash.  

Biting is a serious issue, and unfortunately, it is not a good sign of a typical lab temperment.  With such serious issues, it's often best to work one on one with someone who can see your dog and see the problem in action.  

I suggest you look up a training school and an animal behaviorist as there is little I can tell you online to cure such a serious problem.