Blake Lively thinks having a baby is ''like living with a drug addict''.

The 27-year-old beauty, who married actor Ryan Reynolds in 2012 and gave birth to their first child, James, in December 2014, has revealed living with a newborn child has posed some unusual challenges.

She explained: ''Having a baby is just living in the constant unexpected.

''You never know when you're gonna get crapped on or when you're gonna get a big smile or when that smile immediately turns into hysterics. It might be like living with a drug addict.''

What's more, Blake said having children is ''addictive'' and she is already looking forward to having more.

She told the Los Angeles Times newspaper: ''You have a baby and you think, 'I can't imagine ever not having a baby', because they grow up so quickly. I'd be an 80-year-old woman with a baby if I could.''

Meanwhile, Blake also confessed she doesn't have very positive memories of her most-famous on-screen role, in which she starred as Serena van der Woodsen on 'Gossip Girl'.

She admitted: ''You're part of this machine - this pop culture phenomenon - but as an actor, the quality of your work is definitely compromised because of that.

''When I finished the last season, I didn't feel good at it anymore. I didn't feel stimulated. It had become muscle memory, but not good muscle memory - like bad-habit muscle memory.''