Prankster Roberts tones down scary antics with kids

'Mirror, Mirror' star Julia Roberts has had to "tone down" her scare tactics with twins Hazel and Phinnaeus, seven, and four-year-old Henry - her kids with husband Danny Moder - more than she felt she should.

She told TV talk show host Ellen DeGeneres: "I realised I was getting too much joy out of it so I've had to tone it down... Just like if I hear them coming and they don't know where I am in the house. I crouch down in there private space and they come in and just jump out.