Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey, brain Stuff,
Speaker 1: Lauren Boglebaum. Here it probably sounds more like a scene
Speaker 1: from a horror movie than a scientific reality, but human
Speaker 1: eyelashes are in fact home to iraknids, veritable oodles of them.
Speaker 1: Each individual hair follicle on your eyelids can contain as
Speaker 1: many as twenty five of the creatures. When you consider
Speaker 1: that we humans have up to eighty lashes on our
Speaker 1: lower lids and one hundred and sixty on our upper lids,
Speaker 1: that's possibly some six thousand tiny iracanids living on our
Speaker 1: faces at any given time. It's believed that almost every human,
Speaker 1: no matter how well groomed, has them. Babies are born
Speaker 1: without mites, but they pick them up almost immediately from
Speaker 1: the people around them. Since these tiny beings make themselves
Speaker 1: at home on our faces today, let's get to know
Speaker 1: them a little little better. Many of us think of
Speaker 1: spiders when we hear the word arachnid, but there are
Speaker 1: other types of these eight legged invertebrates, including scorpions, ticks,
Speaker 1: and mites. It's that last category that resides around our eyelashes.
Speaker 1: More specifically, they are mites in the Demodex genus the
Speaker 1: species Demodex filiculorum and Demodex brevis. Unlike many other mites
Speaker 1: that have rounded or bulb shaped bodies, such as dust mites,
Speaker 1: for example, Demodex mites have an unusual elongated body shape,
Speaker 1: with their four pairs of short legs coming off of
Speaker 1: a segment behind their mouth, and then a long abdominal
Speaker 1: section trailing after that. The picture a semi transparent caterpillar
Speaker 1: with only eight stubby legs right at the front. Defiliculorum
Speaker 1: is a bit longer and deebrevis a bit shorter, hence
Speaker 1: the name. The reason you may not have known that
Speaker 1: these follicle dwellers exist is because they're microscopic. They're less
Speaker 1: than a third of a millimeter long, which is around
Speaker 1: the width of a human hair, and smaller than some
Speaker 1: single celled organisms. Most could fit inside a droplet of mist.
Speaker 1: They're small enough that they can wander down into your
Speaker 1: hair follicles and oil glands, and indeed that's where they
Speaker 1: usually hang out during the day. Because they're not fond
Speaker 1: of bright light, these mites live on your lashes so
Speaker 1: that they can eat the oils and skin cells they
Speaker 1: find there. Defolliculorum eats skin cells, while de Brevis prefers
Speaker 1: sebum made by oil glands on the lash line to
Speaker 1: help keep your eyes protected and moisturized. These mites can
Speaker 1: also reside on small hairs throughout the face, including the nose, cheeks,
Speaker 1: and ears, on the neck and chest, and sometimes elsewhere
Speaker 1: on the body, so that six thousand guestimate above may
Speaker 1: actually be on the low end. Neminex mites live short
Speaker 1: lives of about two to four weeks. Their mating habits
Speaker 1: can take in a speed dating quality. The female stays
Speaker 1: on her lash and the males hop from follicled follicle
Speaker 1: looking for a partner. The mites can also jump onto
Speaker 1: another person's face, so if you spend time snuggling with
Speaker 1: a loved one, you're probably providing new mating opportunities for
Speaker 1: one another's eyelash mites. When they die, they decompose in
Speaker 1: your hair, follicles or sebaceous glands. We're not alone in
Speaker 1: being hosts to follicular mites. There are over one hundred
Speaker 1: different species that make their home around the hairs of
Speaker 1: mammals and marsupials, from bats to dogs to armadillos. Most
Speaker 1: of them are harmless or rarely our demodex mites can
Speaker 1: multiply out of control, though, and cause irritation to our
Speaker 1: skin our eyes in the form of demodicosis, a condition
Speaker 1: that can appear as tiny pustules or scales on the
Speaker 1: skin of your face, along with itching or burning. They
Speaker 1: can also cause a type of blepharitis, which is eye
Speaker 1: irritation that comes with swollen or scaily eyelids and lash
Speaker 1: loss or crustiness. Both conditions are treated with lotions, washes,
Speaker 1: or eye drops, with a pesticide to kill the mites,
Speaker 1: other ingredients to help remove excess oil and dead skin
Speaker 1: that they feed on, and something to help soothe the irritation.
Speaker 1: My overgrowth is usually a result of your immune system
Speaker 1: being compromised or suppressed. If that applies to your loved
Speaker 1: one and you see these symptoms, talk to a health
Speaker 1: care provider about it. There is some evidence that, for
Speaker 1: reasons we don't understand, demodex mites might have a role
Speaker 1: in the development of other skin conditions like rseatia and acne.
Speaker 1: Scientists are looking into it. Generally, though these microscopic facerachnids
Speaker 1: are considered harmless, they might even be helpful. Some researchers
Speaker 1: think that they may help prevent clogs in our facial
Speaker 1: pores and may even protect us from the pathogenic bacteria
Speaker 1: that can cause staff and strep infections. Also, there's evidence
Speaker 1: that they're evolving from being parasitic to humans to being
Speaker 1: symbiotic with us. In twenty twenty two, a team of
Speaker 1: researchers published their findings from having sequenced the genome of Defoliculorum.
Speaker 1: They learned a lot during their course of study. Due
Speaker 1: to the mite's isolated lives with no competition from other
Speaker 1: mites with different genes, these creatures have become extremely simple organisms.
Speaker 1: Their tiny legs are powered by just three single cell muscles.
Speaker 1: They also cannot make their own melatonin, which regulates when
Speaker 1: animals sleep and wait, but they can use the melatonin
Speaker 1: created by us they're human hosts to power their night
Speaker 1: long mating sessions. The average human will be host to
Speaker 1: over one thousand generations of mites in their lifetime. We
Speaker 1: really do contain multitudes. Today's episode is based on the
Speaker 1: article so are there really arachnids living in my eyelashes?
Speaker 1: On HowStuffWorks dot com, written by Jennifer Sellers Brain Stuff
Speaker 1: is production of iHeartRadio in partnership with HowStuffWorks dot Com
Speaker 1: and is produced by Tyler Klain. Four more podcasts from
Speaker 1: my heart Radio. Visit the iHeartRadio app, Apple Podcasts, or
Speaker 1: wherever you listen to your favorite shows.