You've probably heard the adage, "Write what you know."
It's good advice for those wondering if they have anything worth writing about. The point is that the people, information, places, and conversations you're involved with are fair game for writing. Any topic can be made interesting, compelling, even fun or funny, if your treatment of that topic works.
But you might also want to write what you don't know. Say you'd like to put something together about aliens invading earth, or weasels doing war dances, or tadpoles. But you don't know the basics of how those things work. (Even in fiction, the reader expects some semblance of reality, whether or not that information makes it into the book.) What do you do? Ask an expert. Like my mom.
Let me explain. I didn't grow up on a farm, but farm animals and farm scenes creep into my writing. Who can resist a wet-nosed calf or a litter of pink piglets? How do I get information about how farms work? I ask my mom. She's my go-to farm girl, with loads of information on chickens and eggs, animal husbandry--that's about animals having babies, to you and me--milking cows and other farmy things.
So today when a critique member (Hi Laura!) wisely asked how all the farm animals in my book were miraculously born in the spring, I called Mom.
"Hi, Mom. Are farm animals usually born in the spring?"
What followed was a story about the hows and whys of animal life on a farm, with a sidebar about the size of chicken eggs.
[In case you're wondering, the answer is yes, farmers plan for their animals to be born in the spring. Who wants to tromp through the snow in the middle of winter to check on a newborn goat when you can simply separate potential moms and dads until it's warmer?]
So, I'd modify the standard adage, "Write what you know" to "Write what you know (Unless Your Mom Knows Better)," or unless you have other experts who can fill you in.