A little boy and a little girl go every day to play in a chicken coop. One day the little girl comes up to the little boy and says, "We can't play in the chicken coop anymore."

The little boy asks, "Why not?"

The little girl answers, "'Cause I'm growing feathers."

The little boy stares at her in disbelief and says, "No way. Show me."

So she pulls down her pants. He thinks about it for a little while and decides it's not that big of a deal, so they both decide to continue playing in the chicken coop.

A few weeks later the little boy comes up to the little girl and says, "We can't play in the chicken coop anymore."

"Why not?" she asks.

"'Cause," he says, "I'm growing feathers, too."

She looks at him in disbelief and says, "No way. Show me!"

So he pulls down his pants. The little girl's eyes widen, and she says, "You're not just growing feathers, you're also growing a neck and a gizzard!"