SWATARA TWP., DAUPHIN CO. Pa.-- Spencer and Sadie are eight months old. They are twins, but to some that is hard to believe.
Mom, Andrea Hosage says, "it's always 'are they twins?' Yes... and I kinda get this look."
In the hospital, Andrea says she even had her doubts after giving birth to the twins.
"What's going on here? I was like, are these really both... obviously with a c-section I saw them but they were across the room."
Andrea says now, there's no doubt in her mind. "He looks just like his dad. She looks just like me, so that's just the way it works out."
But the way it all worked out in this case, isn't so simple.
Doctor Jessica Petko is the Assistant Professor of Biology and Penn State York.
"The father if you flip these over, you'll see that he has the combination of colors in his genes"
She says there are a number of variations in skin pigment based on the parents genetic background.
"In their children, they will each pass on one from each of these pairs... Which one is completely random."
"It could be like winning the lottery. It's just that combination that came from both parents into that child, and yeah, a very rare event, but it happened."
The twins' differences aren't just skin deep either. Andrea says when it comes to things they have in common, there aren't any, "one is doing one thing, one is doing another and they're not on the same schedule."
The differences in schedule not only pertains to sleeping and eating, Andrea says it rings true for to developmental milestones as well.
"It's almost like they split the list in half and he took half and she took half and they're gonna trade skills I guess."
The twins' development isn't the only thing Andrea says she wonders about when it comes to growing up together. "Just the fact that they look so different you know, I wonder if there's gonna be acceptance on one side, where there's not on another."
For now though, Andrea does her part to keep things simple, taking some of the guess work when it comes to being twins, by dressing Spencer and Sadie alike.
"I try to coordinate them as best I can."
Because sometimes, it is the little, simple things that matter. As we learned from Dr. Petko, biracial twins with different skin pigmentation is anything but simple.
"it's not black and white, no."
She says it is impossible to know just how many cases like Spencer and Sadie's exist, because skin color isn't documented at the hospital. She says the only way to really know, is if a parent like Andrea shares her story, like she has with FOX43.
By the way, Spencer and Sadie turn one in September.