# When I rub my eyes, how many of these little \_Demodex\_ bastards do I slay? **URL:** \ **Category:** Factual Questions\ **Created:** [February 20, 2018, 8:45pm UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226 "2018-02-20T20:45:24Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [February 20, 2018, 8:45pm UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/1 "2018-02-20T20:45:24Z")
[These bastards:](https://www.dermnetnz.org/topics/demodex/) There are two mites principally involved in human demodex infestations, _Demodex folliculorum_ and _Demodex brevis_. D folliculorum is found in small hair follicles, particularly the eyelashes. In both its immature and adult stages it feeds on skin cells. D brevis is found in the oil glands that are connected to small hair follicles and feeds on the gland cells. D folliculorum mites are 0.3-0.4mm in length and D. brevis 0.15-0.2mm. This makes them invisible to the naked eye but under the microscope their structure is clearly visible. The 8 legs of this mite move at a rate of 8-16 mm/h and this is mainly done during the night as bright light causes the mite to recede back into the follicle. Ever since I learned about them as a kid I’ve hated them. Commensuralism my ass. I’m happy when I lay waste to them. I can almost hear the drum-playing woman singing “ **Leo** has slain his thousands…” ---
**Author:** ![SamuelA](https://avatars.discourse-cdn.com/v4/letter/s/c77e96/32.png) [@SamuelA](https://boards.straightdope.com/u/SamuelA)\ **Post date:** [February 21, 2018, 3:06am UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/2 "2018-02-21T03:06:04Z")
So get this. Do you know why your poop stinks? Your large intestine and colon and crammed full of very active bacteria. They are digesting whatever you didn’t eat. In fact, they replicate so fast that most of the weight and volume of your poop is bacteria. Most of the gas is stuff they make. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [February 21, 2018, 3:13am UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/3 "2018-02-21T03:13:57Z")
Bacteria can live. ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [February 21, 2018, 6:02am UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/4 "2018-02-21T06:02:21Z")
Ew! Who has those eye bugs? Not me!?!? I hope! ---
**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\ **Post date:** [February 21, 2018, 6:03am UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/5 "2018-02-21T06:03:41Z")
I don’t think rubbing helps you slay lash mites. ---
**Author:** ![Jophiel](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jophiel/32/66_2.png) [@Jophiel](https://boards.straightdope.com/u/Jophiel)\ **Post date:** [February 21, 2018, 6:20am UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/6 "2018-02-21T06:20:05Z")
The obvious solution here is to get your hands on some [Androlaelaps casalis](https://en.wikipedia.org/wiki/Androlaelaps_casalis), a predatory mite that consumes other mites. ---
**Author:** ![Captain\_Amazing](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Captain\_Amazing](https://boards.straightdope.com/u/Captain_Amazing)\ **Post date:** [February 21, 2018, 11:39am UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/7 "2018-02-21T11:39:39Z")
> [@Beckdawrek](#): > > Ew! Who has those eye bugs? Not me!?!? I hope! Pretty much everybody does, unfortunately. The good news is, they’re harmless and you don’t notice them. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [February 21, 2018, 12:33pm UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/8 "2018-02-21T12:33:19Z")
> [@Dr\_Paprika](#): > > I don’t think rubbing helps you slay lash mites. And I don’t think you wanna kill them anyway. Follicular mites are ignored by your body, but dead, decomposing mites would, I assume, cause problems, maybe folliculitis. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [February 21, 2018, 3:16pm UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/9 "2018-02-21T15:16:20Z")
> [@Beckdawrek](#): > > Ew! Who has those eye bugs? Not me!?!? I hope! Depends on how old you are. From the wiki article: > [@](#): > > Older people are much more likely to carry the mites; about a third of children and young adults, half of adults, and two-thirds of elderly people carried them.[6] The lower rate in children may be because children produce less sebum. Recently, a study of 29 adults (18 and over) in North Carolina, US, found that 70% of those 18 years of age carried mites, and that all adults over 18 (n = 19) carried them.[7] This study (using a DNA detection method, more sensitive than traditional sampling and observation by microscope), along with several studies of cadavers, suggests that previous work might have underestimated the mites’ prevalence. However, the small sample size and small geographical area involved prevent drawing broad conclusions from these data. It also indicates that commensalism isn’t the issue any more: > [@](#): > > Demodex were considered commensals but are now considered parasitic. However, in the vast majority of cases the mites go unobserved without any adverse symptoms, though in certain cases (usually related to a suppressed immune system, caused by stress or illness), mite populations can dramatically increase. This results in a condition known as demodicosis or Demodex mite bite, characterised by itching, inflammation, and other skin disorders. Blepharitis (inflammation of the eyelids) can be also caused by Demodex mites.[8][9] Pictures of those things have floated around as prototypical “ugly critter” pictures in various contexts for years. I remember one pinned on a company bulletin board labelled “Typical \ software bug”. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [February 21, 2018, 3:21pm UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/10 "2018-02-21T15:21:16Z")
Interesting factoid. They don’t poop. No anus. Now you might think that’s a good thing, but what it means is that they store up their entire lifetime supply of crap in their bodies, and the entire load is released when they die. ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [February 21, 2018, 4:06pm UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/11 "2018-02-21T16:06:29Z")
> [@yabob](#): > > Interesting factoid. They don’t poop. No anus. Now you might think that’s a good thing, but what it means is that they store up their entire lifetime supply of crap in their bodies, and the entire load is released when they die. Released how? ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [February 21, 2018, 4:12pm UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/12 "2018-02-21T16:12:29Z")
> [@psychonaut](#): > > Released how? Presumably, the body decays. Some writeups on this say they “explode”. I doubt that it’s that dramatic. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [February 21, 2018, 4:14pm UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/13 "2018-02-21T16:14:50Z")
What’s in Demodex poop that makes the situation that more icky? ETA: Thanks on cx. on “commensalism.” So I continue to say: “Get off my lawn.” ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [February 21, 2018, 6:00pm UTC](https://boards.straightdope.com/t/when-i-rub-my-eyes-how-many-of-these-little-_demodex_-bastards-do-i-slay/809226/14 "2018-02-21T18:00:19Z")
I think I am gonna go die now. See ya! You may cremate me and my buggy buddies together. I won’t care anymore.