The TV host - who has fronted the reality show since it launched in 2000 - is set to spend a day in the compound living with the current housemates, after spending months begging bosses to put her in.
The 42-year-old star said: "I've watched it so much I reckon I've got it down on how to be the perfect housemate."
Davina - who is a self-confessed 'Big Brother' addict - had planned to stay in the compound for a full 24 hours, but is now set to leave before bedtime after her husband Matthew Robertson asked her not to.
She explained to Alan Carr during filming of his 'Chatty Man' show: "He said, 'You sleeping is the only bit of you I get to myself'. That's quite a winner isn't it."
Although she has loved working on the programme for the past decade, the brunette star - who has three children, daughters Holly, eight, Tilly, six and three-year-old son Chester - is unsure about whether she would follow it if it gets taken over by Five next year.
She said: "I've spent a year saying goodbye and I don't know if that's a natural time for me to say goodbye and let somebody else take the helm."
Davina's day inside will not be the first time she has entered the compound this year, as entered during 'Big Brother 11's Ignore the Obvious task.