What do you do if your dwarf hamster does not let you pet him?

Go slowly and take your time with the hamster. Feed him from a spoon that you are holding, then gradually work up to touching with a stick. Pet him with the stick for awhile and then try your finger. Eventually the hamster will warm up to you.

If he's a biter, then you should talk to him for a bit so he gets used to your voice, then try. If that doesn't work, make sure your hand does not smell like food or you fed him. Or leave your hand in there for a bit. Dwarf hamsters are known for biting you at first.