Rephrasing means saying the same idea with different words. Here are three easy ways to say your sentences that a 7-year-old can understand:
On the ground, tiny bugs crawl among the flowers and up the tall trees, while butterflies and birds flutter above them. Under the ground, moles dig tunnels next to dinosaur bones and hidden treasures.
Above the earth, little bugs move through the flowers and climb the tall trees as butterflies and birds fly around. Below the earth, moles are busy digging near old dinosaur bones and secret treasures.
Bugs crawl through the flowers and up the tall trees while butterflies and birds flit about. Underneath the ground, moles dig beside dinosaur bones and buried treasures.