Working with Will.I.Am is exhausting, says Nicole Scherzinger

London: Former Pussycat Dolls` singer Nicole Scherzinger says working with rapper will.I.Am on his upcoming album `Willpower` was exhausting.

The 34-year-old said the Black Eyed Peas member is always "always thinking and creating", reported The Daily Star. "He`s like a crazy ball of energy that just bounces off the walls. He`s always thinking and creating," she said. The `X Factor` judge also said that she has worked with will.I.Am on her own solo project. "He executively produced pretty much everything I`ve done, up until now," Scherzinger said.