The obvious difference between little girls and little boys.

Teacher: "Little Miss Muffet sat on a tuffet, eating her curds and whey. Along came a spider, who sat down beside her, and frightened Miss Muffet away."

Now, what could the spider have done to be more polite?

Girl 1: Not just barge in to where she was eating.

Girl 2: Asked if he could sit next to her.

Boy: Kill her.