Her sisters, with their identical looks, would prank teachers by switching places.

"This behaviour might seem like a prank or dare to young people, but it could easily kill someone," said PC Polly Scott, from Northampton's neighbourhood policing team.

A story in the New Yorker recounted an odd prank that Kennedy had pulled several years prior.

It said it was aware of "numerous bomb threats" as well as "swatting incidents", in which prank calls are made to attract a police response to the target's home.

Eliava, in contrast, was a mischievous charmer who pranked his friends, once dressing as a woman to flirt with d’Hérelle at a dinner party, and kept sketchy notes in the lab.