In the end Bilbo could think of no plan except to let the dwarves into the

secret of his ring. He was rather sorry about it, but it could not be helped.
“I am going to disappear,” he said. “I shall draw the spiders off, if I can; and you must keep together and make in the opposite direction. To the left there, that
is more or less the way towards the place where we last saw the elf-fires.”
It was difficult to get them to understand, what with their dizzy heads, and the shouts, and the whacking of sticks and the throwing of stones; but at last Bilbo felt he could delay no longer—the spiders were drawing their circle ever closer. He suddenly slipped on his ring, and to the great astonishment of the dwarves he
vanished.
Soon there came the sound of “Lazy Lob” and “Attercop” from among the
trees away on the right. That upset the spiders greatly. They stopped advancing, and some went off in the direction of the voice.

Chapter 8 Flies and Spiders