Eleven-month-old son and daughter Moroccan and Monroe are already showing star quality, according to their proud father.
Nick, 31, told US Weekly: ''They're talking, and they're singing! They love to sing a lot, and vibe with our music, so it's great!''
The 'America's Got Talent' host - who married Mariah in 2008 - recently quit his US radio show under ''doctor's orders'' after suffering mild kidney failure and blood clots on his lungs.
But he admits the health scare was a wake-up call for him to start taking better care of himself for the people he loves.
He told OK! magazine: ''I want to be there for my children. You want to make sure you're alive more than anything. I'm having a good time, though.
''It's scary when you think about your health - where it can go - but when you're doing it for the right reasons, and I've overcome so much in the past few months, it's good.''
Talking to In Touch magazine, Nick added that he has been taking time out to recover and spend time with his Little Ones.
He said: ''I'm getting my health together. I'm taking time to rest, and getting at least six hours of sleep. I'm putting family first.''