I am an Japanese English teacher. I want my students to experience the same thing as the American kids at the summer camp this year. Please tell me what American children do for joy in the evening or night in summer.
Sitting around a campfire eating s'mores or roasted marshmallows (held over the fire with a twig.)
barbecue-hot dogs, hamburgers, sausages, peppers, onions, chicken..whatever people like.
Singing campfire songs if everyone knows them or telling adventure/scary stories.
Play "capture the flag" (exiting at night but someone could poke an eye on a tree branch by accident)
fishing if it is still light outside
play "duck duck goose" or "red rover"
sorry I can't think of more at the moment
competitions such as tug of war, foot races,
Canoeing, kayaking, diving
ride horses or tractors
ultimate Frisbee (a newer sport, but still a possibility)
Explore the area-cliffs/forest/climb trees.....
do some kind of work like chop wood or construct a simple building (like a shed)