redearslider.com

Do RES bite?

Yes they bite.

But that shouldn't be a concern because if they do it's for a good reason. 1) Either they've mistaken your fingers for food because you are trying to hand feed him which isn't neccesary unless they are sick or in extreme cases or 2) you are handling them in a way they don't like/provoking them. RES are more of a look and don't touch pet. You should only handle them when cleaning their tank or to check over their shell. So you shouldn't have to worry about biting.

mine just push me with their finger, cause they know i control their food

They can bite, either by mistake or intentionally. They don't have teeth, though. If a turtle is small, the biggest reaction you'll most likely have is surprise that it happened so fast. If a turtle, especially a larger one, catches you just right, though, they can break skin.