That midwives' tale about crazy and strange events happening when a full moon is out isn't merely a myth.

A study coming out of Africa is saying that lions are most likely to eat human beings following a full moon.

Lions are predators that hunt most successfully in the dark, which surprises their prey. So it is prime hunting time when deep darkness falls after a full moon.

The research analyzed records of some 500 lion attacks on Tanzanian villagers between 1988 and 2009, and also the size of lions' bellies.

The lions killed and ate humans in two-thirds of the attack, and the majority of the attacks  happened between dusk and 10p.m. when the moon is faint or below the horizon, following a full moon.

The findings also revealed 30 percent more attacks in the second half of the moon cycle, also when there was minimal moonlight.

The researchers say there is less risk of being attacked by a lion during well-lit nights, but the full moon accurately indicates that the risks of lion predation will increase dramatically in the coming days.

Thus the full moon is not dangerous in itself but is instead a portent of the darkness to come.

Rainy seasons also increased lion attacks, as the moon tends to get obscured by clouds.

The findings were published in the Public Library of Science PLOS ONE, an online journal.

The study suggests that other predators, such as the wolf that comes to mind in association with the moon, may be most dangerous following a full moon when the night is dark.

The full moon is a reliable indicator of impending danger, perhaps helping to explain why the full moon has been the subject of so many myths and misconceptions, say researchers.