Rmorse, any animal if it has a mouth can bite you. I think what you are calling a fire leg is the B. smithi (Mexican Red Knee) they are more likely to kick urticating hairs off their abdomen before they rear up on their hind legs (it will look like the first picture he posted) and then if you keep up they will bite you. But usually they will kick the urticating hairs and then try and run away from you.
