It has generated a plethora of scientific papers due to its strange behaviour. Entomophthora muscae lives off houseflies, feeding off them, reproducing inside them, and eventually killing them. Credit:Matt Golding "If you notice a fly with its legs up, lying on its back or even stuck on the flyscreen and it has not moved for a day or two, it’s worth having a closer look," says Dr Teresa Lebel, a fungus researcher based at the Royal Botanic Gardens. To spread, Entomophthora muscae has developed a complex – and disgusting – method of attracting new hosts.

When an Entomophthora muscae spore settles on a housefly, it germinates, cuts through the fly’s exoskeleton and begins infecting the poor creature. Then the fungus heads for the fly’s brain, where it starts manipulating the fly's behaviour. The fungus will force the fly to crawl upward, typically to the top of a branch, flower or stem. It will spread its legs and wings – perhaps to become as noticeable as possible. Then it drools a glue-like substance, likely manufactured by the fungus, that sticks it hard in place. Only then will the fly die.

The fungus will continue growing inside the corpse, digesting the fly, eventually covering the creature’s body in puffy white filaments. For reasons scientists still don’t quite understand, these dead fly corpses are extremely attractive to other houseflies, who inspect, touch and sometimes try to copulate with the cadaver. This is exactly what the fungus wants. The fungus taking over its host fly. Credit:Wiki Commons The fungus grows tiny cannon-like stalks, tipped with a fungal spore, through the dead creature’s abdomen.

When set off by motion from other flies, these cannons explode, spraying fungal spores on any other fly unlucky enough to be nearby. Other fungal spores can float up into air currents and be carried onto prey further afield. This explosion is surprisingly powerful, firing off spores at a velocity approaching 10 metres per second. Loading Despite a large number of studies on Entomophthora muscae, it was not clear just how the fungus had managed to build such an impressive weapon; projectiles so fast are rarely seen in animals or fungi. To find out – and in the hope the cannon could be repurposed to attack other pests – the team of scientists decided to do the only logical thing: they built their own tiny fungus cannon, out of a rubber-like tube with a tiny plastic bullet jammed in the top.