The Visitors by Clifford D. Simak

Forestry student Jerry Conklin is fly-fishing when something huge lands on his car, crushing it into the earth. It looks like a big black box—about fifty feet high and two hundred feet long—and the object stirs up quite a commotion among the townspeople of Lone Pine, Minnesota. One of them even shoots at it—and quickly pays for it with his life.


Around the country, people scramble to determine what exactly the box is. Is it a machine? Or maybe a sentient being? What does it want? They have no way of knowing.


Jerry, meanwhile, has firsthand knowledge after the visitor abducts him. Then, just as he discovers it is a living, intelligent creature, it releases him into the darkness of night.


As Jerry searches for a way back to civilization, more visitors descend upon Earth. They seem harmless enough. Then they begin eating trees, and that's only the beginning . . .