It could be a few things. The first is that you could have the scent of something on you that she wants to eat; for example, a rat or cat. The second is that she may be stress out. This may be because of the enclosure that you have her in, she may not like her hide, or your temps / humidity may not be in the correct range. A third is that she may be in shed.

Do you wash your hands before holding her? What are you keeping her in? What type of hide(s) are you using? What are you using to heat? What are you using to control heat? How is your humidity?