What happens to Huck when he is waiting for the coast to be clear? What does he complain about?

Huck trips over a tree root and made a noise. As a result, Jim sat outside waiting for another noise, so he could see what made the commotion. Little did he know that he was sitting directly between Tom and Huck. Huck's complaint was an incessant itch in his nose, an itch he was afraid to scratch for fear of detection.