One day the spider heard an unusual noise outside her home. It resembled the sound of claws digging into the fabric of Billy's chair. The spider looked nervously up at the rim of Billy's skull.

The next instant two pink paws appeared, followed by a whiskered snout.

A moderate-sized rat, his hind legs on Billy's shoulders, now peered into the spider's home. His black eyes were like twin chips of marble.

"What're you doing in there?" asked the rat.

"This is my home," answered the spider.

"This is a human. A strange human, for it doesn't notice us. But it's still a human. You can't live inside a human."

"But I do."

The rat considered this reply. "No one bothers you?"

"No."

"Is it dry in there?"

"Reasonably so."

"Then I'm coming in to live too."

"You'll break my web."

"I don't care."

The spider in turn considered this assertion. She doubted she could dissuade the rat. And not being poisonous, she had no defense. So she resolved to give in.

"Just let me rework my web. I'll have the rear, and you can have the front."

"Good enough. Hurry up though, before someone comes."

The spider ate her web and restrung it smaller. Then the rat clambered in.

"Don't step on that lump down there," warned the spider. "It makes the house jump."

"Oh, really?" said the rat. He probed Billy's miniscule brain with a claw.

Billy stood up. The rat, growing nervous despite his bravado, retracted his claw. Billy remained standing. The rat lay down with his soft furry stomach across Billy's brain. This caused no further response on Billy's part.

That evening Billy's mother returned to find her son still standing. Although puzzled, she was not overalarmed, but rather proud, as if a new milestone had been reached.

Billy's father did not know what to make of the event either, when told. His reactions were rather similar to his wife's.

"Perhaps Billy is changing."

"Maybe so," said his wife.

Neither thought to check the inside of Billy's head, having been conditioned by years of inactivity to expect no development there.

Another week passed. The rat left on nocturnal forays, but always returned during the day. It was good that he was absent at night, for, with Billy supine, he would have rolled to the back of the skull and crushed the spider's web.

It was a warm summer's day. Billy's mother had left a screenless window open. The rat and the spider were sleeping inside Billy's skull when they were awakened by a raucous voice.

"Hello, folks! What's up?"

Perched on the rim of Billy's skull was a smallish parrot. This parrot had escaped from a neighbor's house, and had been flying rather aimlessly, yet happily about since.

"What do you want?" the rat asked.

"You look so comfy, I was wondering if I could join you," replied the bird.

"No," said the rat. "Go away."

"Come now," said the spider. "You're not the original owner, you know. Why can't the parrot join us?"

"Birds are messy. He'll leave droppings in here."

"I would not," the parrot proudly said. "No more than you would."

"What can you offer us?" continued the rat.

The parrot thought a moment. "I can speak human."

This seemed to intrigue the rat. "Say, that is a handy talent. Okay, you can move in."

"Great!" said the parrot.

And so he did.