"Back off!"

A. pacificus is normally calm and unresponsive, so it's not too easy to get a threat posture. Females will do it more readily than males. Not wanting to frighten her or stress her out, I gently brushed a blade of grass across the front of her palps until she got annoyed enough to give me a piece of her mind! Interestingly, she held this pose for about five minutes, remaining completely motionless. The side photo was taken during this period too.