From WM Briggs, via Chuckles:
St Patrick recruited premenstrual nuns from a nearby convent. He directed these religious to walk before him and spot … snakes, which they did with great efficacy. Once spotted, St. Patrick used his staff to persuade the serpents to head back to England.
St Patrick had tried the same stunt a year earlier, but made the mistake of using nuns who were menstruating. Turns out these nuns spotted snakes about 0.2 seconds slower than premenstrual nuns, which gave the snakes the time they needed to avoid the staff.
It has taken modern science about 1,600 years to confirm the experiment of the sainted Pádraig. Or so say researchers Nobuo Masataka and Masahiro Shibasaki of the Primate Research Institute at Kyoto University.
In the peer-reviewed journal Nature: Scientific Reports, the pair report that in women, “snake detection was found to become temporarily enhanced during the luteal phase as compared to early or late follicular phases.”
The implications are clear. If you plan a little stroll in the forest on Saturday, make sure you take a pre-menstrual woman with you and keep her the forest side of the path. Stands to reason really.