Why does my cat have strange bumps behind her ears and on he

  They feel a bit like scabs and when I was scratching behind her ears I brushed against one of them and my cat acted like it hurt. It's an inside cat whose never been outside and there's one other cat in the house but she doesn't have any of these bumps.
That is not good she needs a trip to the Vet.
It could be a food allergy .... or it could be anxiety. One of my guys gets scabs behind his ears and on his back from excessive scratching ... he also pulls out his hair. He has to be given kitty prozac. It could also be from the other cat .. playing to roughly or not getting along. But a trip to the vet is deff. in order.
It could be a skin infection. Maybe a form of Dermatitis. She should see the vet.
I suggest going to the vet, but it may be a food allergy.
my cat has that too. i call it kitteh acne





not a big deal