Each of those seven baby mice had two biological dads.

It turns out that genetically altered mouse babies born in the same litter as normal mice chirped differently to get their mother's attention, the study found. "The quality and quantity of the ...

"They'll sing them to the females as a courtship behavior," explains Jarvis. It turns out that genetically altered mouse babies born in the same litter as normal mice chirped differently to get their ...

The experiment was repeated 630 times. Although most of the pregnancies failed, seven healthy mice were born. Each of those seven baby mice had two biological dads. This would allow same-sex ...