Why is my kitten attacking my legs and biting my calves?

I have a 10 month old female calico kitten, long haired. I got her from a rescue shelter when she about 3 months old. She is an indoor kitty, and has been the sweetest cat, but randomly has started with a new behavior. She will be in her normal (nice) mood hanging out, and then out of the blue will put her ears back, have a low deep meow, and attack/bite my calves. Then she will back away and hunch her back and attack again (leading to several attempts at biting and clawing my legs). This will last about 10 minutes or so and she goes back to her normal sweet self. Also if she gets in this mood and I happen to be sitting on the ground near her she attacks my arms or my head instead. She has had all of her shots and is perfectly healthy. Why is she doing this- can this problem be reversed? help!!!!