In To Kill a Mockingbird What happens that afternoon in school that alarms the teacher?

i think that she is alarmed at the things 'jumping' out of Burris Ewell's hair, which he calls 'cooties'... i think this is what they called head lice back then. i think Harper lee added this in to show the poverty stricken nature of the Ewell family.

its an awesome book, i havent read something like that in quite some time.