Run, Jump, Whiz, Splash by Vera Rosenberry
Two children, a boy and girl, run, jump, whiz, and splash through the four seasons. Beginning with summer, they run through dewy grass and catch lightning bugs in a jar. This is the first book I've come across that calls them lightning bugs instead of fireflies. For that reason alone, I am a fan of this book. But also, it is quite beautiful and fun. Juliet's favorite part is when they eat cookies at the end. I must admit, I like that part, too.