what does "had the bit in his teeth"mean?
Youngblood had the bit in his teeth. Of all the agents there he had the quickest tongue and one of the clearest minds. He had Johnson’s confidence. He and Roberts had a plan, and neither was in the mood to defer to Kellerman. Indeed, they didn't even consult him. Although Roy was the agent in charge at Parkland, he wasn't told that the new President was to be taken from the hospital. During the next half-hour he talked with both Youngblood and Roberts. Somehow the subject never came up. Only later, by chance, did he learn from his men that Johnson had already left