Turbatrix aceti is a microscopic nematode that is also called the vinegar eel. They tolerate a wide range of acidity and alkalinity, so they can live on the microbes that turn juice into vinegar. An article at LiveScience shows us how they move inside a drop of water.
After roaming the droplet randomly for the better part of an hour, some nematodes began to cluster at the center, while others swarmed to the water's edge, racing around the rim like cars in a roundabout. Soon, individual nematodes began undulating their bodies — then, others nearby started to undulate in sync.
The video was taken by physicist Anton Peshkov of the University of Rochester in New York, so of course he is fascinated with the worms' movement and synchronization while the rest of us are thinking that these icky critters are just looking for something to eat, and when they don't find it, they dance. And when they get tired of dancing, they lean on their partners. Kind of like the dance marathons of the Great Depression.
Watching this synchronized movement is all well and good, but seeing it makes me wonder if these vinegar eels are in our water supply, or in our vinegar. According to Wikipedia, they prefer feasting on mother of vinegar to anything else. They are neither parasitic nor dangerous, but American manufacturers of vinegar pasteurize the product and filter out nematodes before the vinegar goes to market. -via Damn Interesting