It's very clear that first-time mother Carrie Underwood adores her new baby boy Isaiah Michael Fisher, and she sure has a humorous way of expressing her feelings.

The Christian country singer earlier created a Twitter account for her beloved dogs Ace and Penny (@AceandPenny), and this time, she is using their "voices" to tell the world just how wonderful baby Isaiah is, and how the dogs are adjusting to his presence.

"We're not sure about this new thing in our house. Mom calls it our 'little brother.' It's noisy, but makes Mom smile so it can't be all bad!" said the adorable tweet.

Underwood has yet to share the first full photo of baby Isaiah to the world. Right after he was born, Underwood shared on her Instagram account a photo of her son's hands and wrote, "Tiny hands and tiny feet...God has blessed us with an amazing gift! Isaiah Michael Fisher - born on February 27. Welcome to the world, sweet angel!"

Her son's birth is very close to Underwood's birthday which is on March 10. The singer shared some details about her birthday celebration on her Twitter account (@carrieunderwood) and she wrote: "HAPPY BIRTHDAY TO ME! My 1st present = late night date with a tiny semi-bald chubby dude who likes to grunt & cry & pass gas! #bestgiftever"

Her husband National Hockey League (NHL) player Mike Fisher also shared a greeting on his Twitter account (@mikefisher1212) for his wife. "Happy Birthday to the early favorite for mom of the year," he told her.

Fisher earlier tweeted his joy at being a new father. He said, "Thanks for all the prayers and wishes over the past week! Having a child is the best thing in the world!"

Aside from taking care of her baby boy and celebrating her birthday, Underwood is also busy promoting her new fitness clothing line called CALIA by Carrie Underwood with Dick's Sporting Goods.