A fly wound its lazy way through the spring air. It was navigating the fickle air currents of the mildly windy spring day when its antennae picked up on the distinctive smell of carrion. It changed course immediately, first chasing the gusts of air that brought the smell strongest, then circling and descending until it landed on the lid of a black rubbish bin.
It hovered in the area, frustrated beyond endurance and unable to give up when the stench was that strong, until at last a saviour arrived. Some immense force approached, and the fly retreated, but when the top of the black bin opened it saw an opportunity and took it, shooting beneath a large black bag and seeking the source of its temptation.
It ate its fill of chicken carcass, knowing nothing about the nature of the thing, having no sense of the insidious parasite that by now had spread throughout the corpse, no knowledge of its own infection, and lay one hundred and twenty eggs on the rotting flesh.
Now, heavier than before, the fly buzzed madly inside the bin until the lid opened again and then it flew out into the open air, hungry again. It resumed its never ending search for food.
But something was different. Before the end of the day, it was no longer a fly, but a mad thing filled with hunger and desire that it had never known before, and no chicken would satisfy a hunger of this depth. This time, when its antennae picked up on something, it was of a different flavour, and the fly homed in on the source eagerly.
A man stood barbequing sausages in his backyard. The fly did not smell the sausages at all, only flesh. It landed on the man’s shoulder as he flipped the meat, and bit him there. It didn’t consume, only bit and bit and bit, and soon so lost in its own ecstasy that it couldn’t get away from the descending spatula fast enough, and the man wiped a black smear from his shoulder a few seconds later, swearing.
In time, maggots hatched and escaped from the black bin, and took to the wind as their mother had. In time, they all found plenty of food, and though none of it was the kind they’d evolved to seek, it seemed to satisfy them all the same.