Scientists in Sweden have figured out the chemical structure of the protein ZP3 in mice, which coats all mammals' eggs and with which sperm must bind to complete conception. Mice bred without the protein are infertile, and human women with abnormal ZP3 often have fertility problems. Scientists say that this discovery could lead to a non-hormonal birth control pill that disrupts the production of the protein in human women, thus preventing pregnancy. But would you take it? [New Scientist]