Peritrich: hairy, relentless, and brilliantly simple.

When you picture a bacterium, you might imagine a simple, smooth sausage-shaped cell. But look closer—really close—and you’ll see that some bacteria have traded subtlety for spectacle. Enter the peritrich .

The name comes from Greek: peri (around) and trich (hair). And that’s exactly what a peritrich bacterium looks like: a microscopic creature wearing a furry coat. But these aren’t just for warmth. Those "hairs" are , long, whip-like filaments of protein that spin like tiny propellers. A Crown of Propellers In a peritrichous arrangement, flagella sprout from everywhere —the sides, the front, the back. Imagine a hot dog covered in spaghetti, or a submarine with dozens of outboard motors glued to its hull. The most famous example? E. coli , the superstar of your gut microbiome.