Rebecca Romijn left exhausted by twins

Rebecca Romijn says her twin daughters are leaving her exhausted because they won't go to bed.

The 'X-Men' actress admits Dolly and Charlie - her children with husband Jerry O'Connell - have become more difficult to raise since they turned two in December because they won't sleep and keep getting sick.

She joked to People: "It's (parenting) equal parts absolutely adorable and absolutely horrible! I'm just trying to get them to bed at night, but they're two! That's what being two is all about!

"Right now, I think the whole job of being a two year old is just trying to get as sick as often as possible to build up your immune system. It's been three months of fevers, colds and vomiting."

Rebecca admits she and Jerry are delighted if they can just get a good night's sleep.

She added: "There have been so many sleepless nights for my husband and I.

"If I can just get the girls to stay in their beds and shut up at night, I'm happy."