I was driving and heard a scratching in left front thought it was a rock so took the wheel off no rock what else could it be thanks

 

Something stuck between rotor and pads? Hard to say with so little info...

 

Check the rotor shield on the innerside. It could be touching the rotor since they are very close to begin with and might have got bent to touch. Other than that, your pads could be low enough as to be scratching and not necessarily squeeling. They do both when low and rubbing from either wear or caliper drag.

 

If nothing else, lift the front end off the ground and turn the wheel by hand

 

I am guessing the pads are low it is squealing now just hate taking the tire off snow everywhere here and I have to do it in my driveway anyway thanks for the help