Because Bob ran down the road. He fell over.

The thunder roared and the hobbits hid.

Bilbo had slept in a cave , then the goblins attacked.

The cart came to a wheezing halt as Gandalf  strode into the hobbit hole.

Jim was interested in the idea. He rang his friend to let him know.

Owls are nocturnal. This means they are very active at  night. They  also have excellent eyesight.