It’s been a week since the last full moon on 15th July. During this time, the odds of being attacked by a lion are highest than at any other point in the month, which is why I’ve been walking around the neighbourhood with two guard bears and a platoon of ninjas. The fact that I live in a leafy suburb of London is inconsequential. You can never be too careful. Constant vigilance.

Of course, lion attacks are more of a problem in other parts of the world. In Tanzania, lions have attacked more than a thousand people between 1988 and 2009, and eaten around two-thirds of them. Now Craig Packer from the University of Minnesota has shown that the frequency of these attacks is tied into lunar cycles.

Texan-born Packer first visited Tanzania in 1972 to study baboons with Jane Goodall. When he returned to the country in 1978, his attention had shifted to lions and it has never left. His team expanded upon records of local lion prides that began in the 1960s, creating a massive set of data on over 5,000 individuals from the Serengeti National Park and ...