Jessica Alba tells her kids their lost items are ''up their butts''.

The 37-year-old actress has daughters Honor, nine, and Haven, six, and son Hayes, three months, with her husband Cash Warren, and has admitted her ''terrible habit'' when it comes to parenting her tots is being unhelpful whenever they've lost something.

She said: ''I have this terrible habit: Whenever my kids ask me to find something, they're like, 'Mom, where's my...' you know, backpack, toothbrush, whatever. And I just say, 'Up your butt,' and that's probably bad parenting. But they get to a certain age where I'm like, 'That's where it is: It's up your butt.''

It isn't all jokes in Jessica's home, however, as she admits she wants her brood to see her outside of her ''comfort zone''.

She added: ''I want my kids to see me push outside my comfort zone. And sometimes that means making mistakes and admitting them, which is especially hard in front of your kids.''

The 'Fantastic Four' actress and her film producer spouse - who wed in 2008 - often battle hectic schedules, and so they have established Family Fridays, in which they always spend the day together.

Jessica told InStyle: ''It's our game night. We get on teams and play Clue. Honor is really good. I love when she wins - she's strategic.''

Her comments come after she recently revealed she has learned to ''cherish every messy moment'' with her children.

Posting a photo of herself with her children on social media, the 'Sin City' actress wrote: ''Motherhood: it's a doozy, isn't it? Your world gets turned completely upside down. Everything you thought you knew about what was important is no longer. And all the things you once took for granted - like sleep, and sitting down to eat an actual meal - become the greatest luxuries. Little people change you. To love and need someone that much and have them love and need you just as much...it's the best and hardest and most heartbreaking thing there is.

''I still can't believe it, but my oldest baby is almost 10 years old. And you know what? She doesn't need me in the same ways she once did. There goes that heartbreak again...but it's true. The time we have with our little ones when they're actually little is so fleeting. And it's a reminder for me to be present and cherish every messy moment. Every tantrum, every tired cry, every bit of these days that sometimes feel like they'll never end. Because the truth is, they will. (sic)''