# Why do flies land on humans? **URL:** \ **Category:** Factual Questions\ **Created:** [June 9, 2006, 6:20pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092 "2006-06-09T18:20:46Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![sabrinabr](https://avatars.discourse-cdn.com/v4/letter/s/71c47a/32.png) [@sabrinabr](https://boards.straightdope.com/u/sabrinabr)\ **Post date:** [June 9, 2006, 6:20pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/1 "2006-06-09T18:20:46Z")
Are we just a nice resting spot? I don’t think we taste good. What is the point to the aggravation? ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [June 9, 2006, 6:27pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/2 "2006-06-09T18:27:26Z")
Doofus. YOU don’t have to think we taste good. THEY do. Do you like the taste of dog shit? The flies land us to A) see if there’s anything worth eating, and/or B) see if there’s a good place to lay eggs. Probably, occasionally to rest. Sometimes, there’s A. Seldom B, unless we’re dead. Never to aggravate us. That’s anthropomorphizing to extremes. Like a fly cares what you think. Get a grip, Looie. ---
**Author:** ![Lissa](https://avatars.discourse-cdn.com/v4/letter/l/85f322/32.png) [@Lissa](https://boards.straightdope.com/u/Lissa)\ **Post date:** [June 9, 2006, 6:41pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/3 "2006-06-09T18:41:08Z")
I wonder, can they can smell us? I’ve never heard anything about flies and their sense of smell. I imagine we’d have to smell pretty tasty, covered in sweat and dead skin cells, with fats from lotions and traces of flower and animal oils in perfumes. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [June 9, 2006, 6:45pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/4 "2006-06-09T18:45:21Z")
Flies in fact are tasting us, just to find out how full of shit a given individual might be. (I might worry if one keeps coming back. 😉 ) However, they are also probably getting necessary nutrients by licking up liquid or dried perspiration, dead cells, and skin oils or other secretions. ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [June 9, 2006, 6:48pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/5 "2006-06-09T18:48:08Z")
They will take a bite and drink your blood. Nothing ruins a hike more than deer and horse flies. The swarms of black flies can drive people insane in the northern areas. ---
**Author:** ![Rico](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rico/32/3582_2.png) [@Rico](https://boards.straightdope.com/u/Rico)\ **Post date:** [June 9, 2006, 7:46pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/6 "2006-06-09T19:46:21Z")
\ **CC** , this is GQ. Drop the vitriol a few notches, OK? \ ---
**Author:** ![blinkingblinking](https://avatars.discourse-cdn.com/v4/letter/b/ea5d25/32.png) [@blinkingblinking](https://boards.straightdope.com/u/blinkingblinking)\ **Post date:** [June 9, 2006, 8:33pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/7 "2006-06-09T20:33:34Z")
> [@sabrinabr](#): > > Are we just a nice resting spot? I don’t think we taste good. What is the point to the aggravation? I would like a serious answer to this. The fly never gets any food from us (does it?). So why land on us. There are other resting places. And, why do they keep buzzing and buzzing around our face. What does that achieve for the fly? ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [June 9, 2006, 8:51pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/8 "2006-06-09T20:51:52Z")
Yes, I apologize. I was a most ungracious and unwelcoming host. I only meant to convey, well, never mind. I was unnecessarily crass. A terrible ambassador for a marvellous location on the net. I’m truly sorry. Flies hover because they sense the heat and odors that indicate the liklihood of something potentially nourishing - the gunk that grows on our surface when we sweat and the bacteria starts up on it, and probably the lovely CO2 and our breath that also indicates spoilage (i.e. lunchtime for muscus domesticus). If they can set down for a few moments to rest, so much the better. But they’re really looking for rot, and probably to a fly, that’s what we smell like, especially when we’re warm, and especially when we’ve got our mouths open. Go outside and sleep with your mouth open and see how long it takes before you get visited by a six-legged dental hygenist. ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [June 9, 2006, 8:57pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/9 "2006-06-09T20:57:54Z")
> [@blinkingblinking](#): > > I would like a serious answer to this. The fly never gets any food from us (does it?). So why land on us. There are other resting places. > And, why do they keep buzzing and buzzing around our face. What does that achieve for the fly? According to Bill Bass, the creator of the “Body Farm” at the University of Tennessee at Knoxville, in his book _Death’s Acre_, flies that come to investigate a corpse they’ve put out for decomposition observation will also check out any living observers, especially around the faces. He says that faces and wounds provide nice soft tissue for eating and for laying eggs in. So flies are hoping you’ll provide dinner for them, and probably for their future offspring maggots. ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [June 9, 2006, 9:06pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/10 "2006-06-09T21:06:31Z")
I was serious. They want your blood. I still have a dent in my wrist where a horse fly took out a chunk. Flies are merciless to animals ears. They will chew them until thy are tattered. Then more show up for the blood from the wounds. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [June 9, 2006, 10:58pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/11 "2006-06-09T22:58:14Z")
> [@blinkingblinking](#): > > I would like a serious answer to this. The fly never gets any food from us (does it?). So why land on us. There are other resting places. See my post above. Yes, they probably do obtain some nutrients simply by licking our skin when they land. In the tropics, “sweat bees” can be real pests because they will land on you just to drink your sweat for the salt. Butterflies do this to. ---
**Author:** ![LiveOnAPlane](https://avatars.discourse-cdn.com/v4/letter/l/3d9bf3/32.png) [@LiveOnAPlane](https://boards.straightdope.com/u/LiveOnAPlane)\ **Post date:** [June 10, 2006, 12:08am UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/12 "2006-06-10T00:08:34Z")
Uh, you do realize that we are talking about different flies here, right. What **sabrinabr** is talking about seems to be “regular” flies, and what **Harmonious Discard** is talking about is biting flies. Completely different situation. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [June 10, 2006, 2:22am UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/13 "2006-06-10T02:22:36Z")
> [@LiveOnAPlane](#): > > Uh, you do realize that we are talking about different flies here, right. What **sabrinabr** is talking about seems to be “regular” flies, and what **Harmonious Discard** is talking about is biting flies. > > Completely different situation. Yes, **sabrinar** would seem to be talking about [House Flies](http://en.wikipedia.org/wiki/Housefly) _Musca domestica_, and perhaps some other kinds of flies, while \*\*Harmonious Discord \*\* is talking about biting flies, some of which belong to the family Tabanidae and some to other families. It is estimated that there are more than 200,000 species in the family Diptera, which includes flies, mosquitoes, and other kinds of insects. ---
**Author:** ![Sattua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sattua/32/11906_2.png) [@Sattua](https://boards.straightdope.com/u/Sattua)\ **Post date:** [June 10, 2006, 2:58am UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/14 "2006-06-10T02:58:55Z")
> [@Colibri](#): > > See my post above. Yes, they probably do obtain some nutrients simply by licking our skin when they land. In the tropics, “sweat bees” can be real pests because they will land on you just to drink your sweat for the salt. Butterflies do this to. Does Indiana count as the tropics? Because there are insects here like tiny bees that always hover around sweaty people–and my mother always called them sweat bees. I don’t know if they sting or not. I don’t think their wings make an audible buzz, either. But they’re striped. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [June 10, 2006, 3:07am UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/15 "2006-06-10T03:07:02Z")
> [@Sattua](#): > > Does Indiana count as the tropics? Because there are insects here like tiny bees that always hover around sweaty people–and my mother always called them sweat bees. I don’t know if they sting or not. I don’t think their wings make an audible buzz, either. But they’re striped. There are plenty of [sweat bees](http://www.everythingabout.net/articles/biology/animals/arthropods/insects/bees/sweat_bee/) in temperate areas, they are just a particular nuisance in the tropics. ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [June 10, 2006, 3:25am UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/16 "2006-06-10T03:25:12Z")
Though I mention the bite of a horse or deer fly, Idon’t exclude house flies. The house flies are the same ones as the farmers call barn flies, and they do eat the ears of cattle and other livestock. You have to stay diligent in spraying and use bug zappers. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [June 10, 2006, 4:33am UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/17 "2006-06-10T04:33:02Z")
> [@Harmonious Discord](#): > > Though I mention the bite of a horse or deer fly, Idon’t exclude house flies. The house flies are the same ones as the farmers call barn flies, and they do eat the ears of cattle and other livestock. You have to stay diligent in spraying and use bug zappers. I don’t know what species you are referring to as a “barn fly,” and a quick google search doesn’t produce any clear information on it. However, the [stable fly](http://www.everythingabout.net/articles/biology/animals/arthropods/insects/bees/sweat_bee/) closely resembles the house fly, but is a different genus. It has biting mouthparts, and is a pest of cattle in stables and barns. The true House Fly \*Musca domestica \* lacks biting mouthparts, and can only basically sponge stuff up. If the flies you mention bite or chew, then they are definitely not House Flies. ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [June 10, 2006, 12:34pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/18 "2006-06-10T12:34:40Z")
That is a sweat bee page. Barn flies are just a local term I guess to refere to the black flies found in a cattle barns. They may not start the wounds but they make them bigger, by sucking on the wounds. They may be stable flies, I don’t know. They also scower the hairs for the sweat. ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [June 10, 2006, 5:55pm UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/19 "2006-06-10T17:55:03Z")
> [@blinkingblinking](#): > > I would like a serious answer to this. The fly never gets any food from us (does it?). So why land on us. There are other resting places. > And, why do they keep buzzing and buzzing around our face. What does that achieve for the fly? We sweat, we smell (emit odors), they smell (sense odors) in some way. And here they come. Sniff some fly trap attractant, just for kicks! Nasty smelling, isn’t it? ---
**Author:** ![FlyingRamenMonster](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@FlyingRamenMonster](https://boards.straightdope.com/u/FlyingRamenMonster)\ **Post date:** [June 11, 2006, 5:09am UTC](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092/20 "2006-06-11T05:09:49Z")
And occasionally, they land on people to take a shit. This has happened to my dad. Twice. [Next page](https://boards.straightdope.com/t/why-do-flies-land-on-humans/360092.md?page=2)