Rocker Pete Wentz and wife Ashlee Simpson-Wentz are already showing signs of great parenting - less than 24 hours after welcoming baby Bronx Mowgli into their family.

Singer/actress Simpson-Wentz gave birth to their first son on Thursday night - and the tot's grandparents are delighted with the new addition.

Joe and Tina Simpson say in a statement, "We are happy beyond words and incredibly proud of Ashlee and Pete.

"They are unbelievable parents already, and we can't wait to spend Bronx's first holidays together with the whole family. We are truly blessed."

And the Fall Out Boy bassist's parents are equally excited - revealing the newborn is quickly showing similarities to his mum and dad.

Pete Sr. and Dale Wentz add, "We're thrilled. (Bronx) stayed up late the first night, smiling at everyone who came into the room. He already seems to have the independence and charm of both of his parents."