In Chapter 3 in To Kill A Mockingbird: What happens that afternoon in school that alarms the teacher?
After Scout brings Walter Cunningham home for lunch with them, they return to school to find Miss Caroline shrieking in Chapter 3 of To Kill a Mockingbird. Little Chuck Little and the other boys believe that she has seen a mouse, but instead she points to a particular boy's head, whereupon Chuck tells Miss Caroline, "There ain't no need to fear a cootie, ma'am" and picks one from the boy's head and crushes it. "Miss Caroline watched the process in "horrid fascination" while Little Chuck brought her water in a paper cup.
Next, the teacher addresses the boy with the "cooties," asking him his name; after Burris Ewell answers, she asks him to spell it. Burris cannot spell. So, pulling a large book from her drawer Miss Caroline reads some ...[she] suggests that he go home and wash his hair in lye soap and then treat his scalp with kerosene. As he asks her why, the Burris boy becomes combative, laughing rudely, "You ain't sending me home...I was on the verge of leavin'--I done done my time for this year." He laughts rudely when Miss Caroline looks puzzled, but one boy calls out ," He's one of the Ewells."