Lucie did this when I first got her (still does to people who let her) she never made us bleed, but it took a couple days to get her to finally stop. She saw feet as something that moved for her to play with
she goes after hands too. We just kept telling her NO! and then would pick her up and move her away until she stopped. She still tries chasing my mom around biting at her slippers, but my mom allows her to..
Try giving her a stern No, and move her away from your feet.