Philip K. Dick: Tony and the Beetles
A TEN-YEAR-OLD BOY GROWS UP FAST WHEN HISTORY CATCHES UP WITH THE HUMAN RACE.

Tony is a normal 10 year old boy living on the colony world with his parents and other humans who run this world. The 'Beetles' as the natives are called in derision, do the work andt know their place. Their fleet was defeated with little problem 10 years ago and the humans had yet another world to populate with their overflowing numbers on Earth. But today something was happening; the Beetle fleet had returned and was doing nasty things to the earth vessels. Is it possible that the inexorable human expansion to new systems and planets across the galaxy was coming to an end? What would happen now?