When Rebecca Chadwick heard something odd coming from baby Jack's car seat, she couldn't help but record it.

While napping, 7-month-old Jack babbles adorably in his car seat as his mother watches. According to the YouTube video description, Chadwick thinks that her sleeping angel must have been dreaming about his father, given the repetition of "da da da da" throughout his monologue.
According to Live Strong, this sort of behavior is common in babies though the exact nature of the sleep talking varies from case to case. As the infant moves through sleep cycles, they may occasionally grunt, whine, babble, or even laugh. As long as the baby does not show signs of difficulty when breathing, these little noises are nothing to worry about.