A sleepy Burmese snake named Mary at the Artis Zoo in Amsterdam has become the first known python to clone itself. Reptile curator Eugene Bruins announced this spring that nearly 40 percent of Mary's unhatched eggs harbor tiny embryonic replicas. Several snake species are known to reproduce without sperm, a process known as parthenogenesis, though the phenomenon has never been documented in pythons. Stranger still, the embryos are all female, a first for parthenogenic snakes, whose chromosome setup typically produces males only. The Artis Zoo plans to hatch the eggs to see if they inherited Mary's cloning powers. Meanwhile, Mary is being kept far from any male: A single conjugal visit and "the whole special thing would stop at once," Bruins warns.