Chicken laying eggs inside eggs

IDAHO FALLS, Idaho (KIFI) – A local chicken is producing eggs inside other eggs continuously on a family chicken coop in Idaho Falls.

The Rosenkrance family got their first set of chickens back in May, and a couple weeks ago stumbled upon a massive egg.

"My daughter likes to go check for eggs in the morning, and so she came in and she had this huge one that looked like a potato and we were just shocked," Madison Rosenkrance said.

She said they had gotten some bigger eggs with double yolks, but this was much bigger than those.

As a family, they cracked the egg open and found another smaller egg inside.

The first occurrence was a few weeks ago, and since then Emma, the hen, has laid six eggs within an egg so far.

"It was every two days for like a week, and now it's gotten a little more spaced out, and we've noticed she's laid some normal eggs. So, I don't know if she's just figuring it out or if she'll keep laying them or start laying normal eggs regularly," Rosenkrance said.

According to University of California Santa Barbara, "this is quite a rare event called counter-peristalsis contraction."

The egg, once formed in the chicken, starts traveling backwards through the oviduct and cycles back through the egg formation process, placing the current egg inside another.

Ron Patterson, University of Idaho Extension Educator in Bonneville County, backs up the claim. He says, "Very few people ever see it in person."

It basically comes down to Emma's genetics. This isn't an unhealthy phenomenon, her body just has an interesting way to produce her eggs.