London, Sep 7 - Hollywood actor Brad Pitt has spent more than $80,000 building a place for his children's gerbils.

Pittt is fascinated by design and construction and personally oversaw every step of the project at his family's French estate, reported thesun.co.uk.

It features a maze of tunnels, seesaws and platforms for the pets.

'Pitt had so much fun putting the place together with his kids Maddox, Zahara, Shiloh and Pax,' said a source.

'It's incredibly complex and cost a lot but Brad's more than happy with any activity that can combine his two passions - his kids and architecture,' added the source.