Something bite me back of my ear is red just red don't hurt ......i want to know if is a spiders or something bad?

Have it looked at: It's hard to tell without seeing it what bit you. It's unlikely that it was a spider (or at least a venomous one) because spider bites are typically painful. I would recommend to go to your doctor to have it looked at . If you live in a wooded area where you could've gotten bitten by a tick, bloodwork should be done to rule out lyme disease. Good luck!