Kelly Clarkson and Brandon Blackstock have been trying for a baby "like rabbits”.

The 'Because Of You' hitmaker and her new husband are spending all their spare time in bed to get pregnant as soon as possible.

Rabbits have an extraordinarily high sex drive, something the 31-year-old singer says she can identify with as she is so desperate to have a child.

Speaking on The Tonight Show With Jay Leno on Monday, Kelly said: "We want a baby now! Practice makes perfect! We're trying, trying, trying ... Like rabbits!"

The former American Idol winner says becoming a step-mother to Brandon's children from a previous relationship - Savannah, 11, and Seth, seven - has made her want more maternal than ever.

She said: "We have two kids. And they're so great. And I never wanted kids before, but now I want, like, five."

However, Kelly fuelled rumours she might already be expecting her first child when she refused to give a direct answer to Jay's questions.