Sienna Miller accidentally made two rabbits mate as a child.
The 'G.I. Joe: The Rise of Cobra' star was an ''eccentric'' child and her curiosity led to her making two pets breed at boarding school.
She told the Mail on Sunday's Event magazine: ''I was apparently quite eccentric too ... I went to boarding school when I was eight, which is quite young, so you were allowed to take a pet with you a company.
''I took my pet rabbit, and another girl, Ali, had a rabbit too. Well, they got on and I wondered what would happen if I put them together, and they ended up mating.
''I bred, quite by accident, five bunnies, one of whom went on to be a prize-winning rabbit by complete coincidence.''
The star also revealed she is ''superstitious'' and has a ritual she has to go through every time she is boarding an aeroplane.
She admitted: ''I'm quite superstitious. When I get onto a plane I have to kiss my hand three times and tap the plane three times. If I didn't do that and the plane went down I'd know it was my fault.
''My father actually grabbed my hand once and refused to let me do it to prove a point, and we went through the worst turbulence that either of us has ever experienced, and I looked at him and thought, 'See, I knew this would happen!' ''