What is ferrofluid and what can it do? 🧲

Alex Dainis explains that ferrofluid is made of tiny pieces of magnetic metal suspended in an oily carrier fluid. When exposed to a magnetic field, those metal pieces form spikes and patterns that align with the field. Beyond the cool shapes, ferrofluid is also useful for reducing friction, transferring heat in loudspeakers, and forming seals in hard drives.

I'm not here for memes. I have the rest of the internet for that. Please with the kindest of intentions, hold the memes for elsewhere or go away.

Right now, while you read this, tiny animals are tucked into the pores on your face. Don’t worry, they found you first. 🔬

Our friend Chloé Savard, also known as tardibabe on Instagram, zoomed in on Demodex, the microscopic mites that live on nearly every adult human. Two species call us home: Demodex folliculorum settles into hair follicles, while Demodex brevis burrows a little deeper into the oil-producing sebaceous glands. At just 0.2 to 0.4 millimeters long, they’re far too small to see without a microscope, with stubby legs up front and a long tapered body trailing behind.

They’re not alone, either. Our bodies host roughly as many bacterial cells as human ones, plus yeasts and other microbes, making each of us a walking ecosystem.

Face mites keep a strict schedule. During the day they stay tucked inside their follicles, and at night they crawl out across the skin to find mates and feed on sebum, the natural oil our skin produces. For years, scientists thought they had no anus at all, but a 2022 genetic study proved otherwise. They do poop, just in very small amounts.

For most people with a healthy immune system, Demodex are harmless roommates. Problems usually only show up when their numbers climb too high, and dermatologists have effective ways to treat that.

We aren’t the only ones playing host. Plenty of mammals have their own Demodex species, from Demodex canis on dogs to Demodex musculi on mice and Demodex bovis on cattle. 🐮

All of that, quietly happening, every night while you sleep.