second grade analogies

As you probably do not know, I work at a summer camp and rule the second graders. I have been doing this for 3 years and I usually know what to expect from hyperactive, whiny, nok-hockey experts. Much to my pleasure, the kids will have intellectual arguments within ear shot. Yesterday they discussed space travel, "It takes a mile to get to the moon right?" and today i heard a charming conversation about the future:

"i wonder what we'll look like"

"the same just taller"

"maybe we'll turn into robots"

"nooooo. If we're not robots now, we wont be then"

"yeah we'd need batteries"

"you know, the heart is like a battery"

"yeah"

(long thoughtful pause)

"yeah"