Scientists who study this fungus and its effect on house fly hosts were previously surprised to see that healthy male flies in the laboratory were unusually interested in mating with dead, infected females, said Andreas Naundrup Hansen, a microbiology researcher at the University of Copenhagen and lead author of a new study on this previously unknown aspect of the fungal infection.

“We were very curious about this odd behavior, as it obviously seemed dangerous to the copulating male to have intimate contact with cadavers that were actively discharging infectious conidia (spores),” Hansen told Live Science in an email.