# Why did this housefly have live maggots inside? **URL:** \ **Category:** Factual Questions\ **Created:** [June 27, 2008, 4:27pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456 "2008-06-27T16:27:30Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![RedSwinglineOne](https://avatars.discourse-cdn.com/v4/letter/r/a9adbd/32.png) [@RedSwinglineOne](https://boards.straightdope.com/u/RedSwinglineOne)\ **Post date:** [June 27, 2008, 4:27pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/1 "2008-06-27T16:27:30Z")
Yesterday, while in my kitchen, a housefly flew by. Without thinking, I swatted it out of the air with a kitchen towel. It bounced off the wall and lay on the floor motionless. I thought to myself, “Cool. I’ve got a new macro lens for my camera, I’ll use it on the fly and see what I can see.” When I went to move the fly, it was still moving, so I stuck it with a wooden skewer to kill it, and so I could move it outside. But when I stuck it, some of its guts squirted out its side. As I cleaned it up, I noticed its ‘guts’ were trying to crawl away. It’s ‘guts’ were actually a mass of tiny maggots. For an instant I thought, “gross, it was pregnant.” But then I realized flies don’t lay live maggots, they lay eggs. So why did [this fly](http://s274.photobucket.com/albums/jj271/SPORTYBUELL/?action=view¤t=P6261120-cropped.jpg) have live maggots inside? I was thinking maybe some kind of parasite, but I can’t find any info on a parasite like this. It seems they often have a kind of mite under there wings, which it seems to have [here.](http://s274.photobucket.com/albums/jj271/SPORTYBUELL/?action=view¤t=P6261140-mite.jpg) There is also a wasp which lays an egg in the pupal case, where it feeds on the pupa. For those interested, here are some photos of one [maggot](http://s274.photobucket.com/albums/jj271/SPORTYBUELL/?action=view¤t=P6261128-cropped.jpg) [crawling](http://s274.photobucket.com/albums/jj271/SPORTYBUELL/?action=view¤t=P6261129-cropped.jpg)[out.](http://s274.photobucket.com/albums/jj271/SPORTYBUELL/?action=view¤t=P6261130-cropped.jpg) ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [June 27, 2008, 5:01pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/2 "2008-06-27T17:01:40Z")
Cool pictures. Maybe it was a tiny fighter fly from another galaxy and you just saw the crew escaping? ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [June 27, 2008, 5:27pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/3 "2008-06-27T17:27:31Z")
It may very well be the fly had internal parasites. Here is a Youtube vid of a cricket… [![]( " - YouTube") ](https://www.youtube.com/watch?v=xu9bqt2OgFM) ---
**Author:** ![Mosier](https://avatars.discourse-cdn.com/v4/letter/m/7ea924/32.png) [@Mosier](https://boards.straightdope.com/u/Mosier)\ **Post date:** [June 27, 2008, 5:28pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/4 "2008-06-27T17:28:44Z")
I want to keep this close to the top until it gets answered, because this is the coolest thing I have seen in a long time! ---
**Author:** ![RedSwinglineOne](https://avatars.discourse-cdn.com/v4/letter/r/a9adbd/32.png) [@RedSwinglineOne](https://boards.straightdope.com/u/RedSwinglineOne)\ **Post date:** [June 27, 2008, 9:15pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/5 "2008-06-27T21:15:31Z")
[QUOTE=Enola Straight] It may very well be the fly had internal parasites.] [/QUOTE] That is what I assumed, but I was surprised I couldn’t find anything on the internet. I though they must be rather common. I wouldn’t expect that the first fly I skewer since I was 10 had some unusual condition. The volume of maggots seemed rather large compared to the size of the fly. There were at least 20-30 of them in the first blob that came out, and I don’t know how many more were still inside. It seems surprising that the fly was still flying with all of those in there if they were eating their way around. Flies aren’t complicated creatures, but still… [QUOTE=Enola Straight] Here is a Youtube vid of a cricket… ![](https://img.youtube.com/vi/xu9bqt2OgFM/maxresdefault.jpg)https://www.youtube.com/embed/xu9bqt2OgFM?feature=oembed&wmode=opaque [/QUOTE] That’s just creepy. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 27, 2008, 10:03pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/6 "2008-06-27T22:03:26Z")
What was inside the maggots? Don’t tell me you didn’t bother to check. ---
**Author:** ![RedSwinglineOne](https://avatars.discourse-cdn.com/v4/letter/r/a9adbd/32.png) [@RedSwinglineOne](https://boards.straightdope.com/u/RedSwinglineOne)\ **Post date:** [June 27, 2008, 10:19pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/7 "2008-06-27T22:19:32Z")
[QUOTE=Mangetout] What was inside the maggots? Don’t tell me you didn’t bother to check. [/QUOTE] Nope. I didn’t really want to know what was inside the fly for that matter. That information just kind of presented itself. ---
**Author:** ![lizardling](https://avatars.discourse-cdn.com/v4/letter/l/f4b2a3/32.png) [@lizardling](https://boards.straightdope.com/u/lizardling)\ **Post date:** [June 28, 2008, 12:18am UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/8 "2008-06-28T00:18:34Z")
_runs away screaming into the early evening_ My guess is that it’s something that parasitizes the common housefly, like what \*\*Enola \*\* said. _scrubs self all over_ (WHY did I open this thread?) ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [June 28, 2008, 5:03am UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/9 "2008-06-28T05:03:01Z")
> [@Jonathan Swift (1733)](#): > > So, naturalists observe, a flea > Has smaller fleas that on him prey; > And these have smaller still to bite ’em; > And so proceed ad infinitum. .. ---
**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:** [June 28, 2008, 11:41am UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/10 "2008-06-28T11:41:06Z")
[QUOTE=RedSwinglineOne] When I went to move the fly, it was still moving, so I stuck it with a wooden skewer to kill it, and so I could move it outside. But when I stuck it, some of its guts squirted out its side. As I cleaned it up, I noticed its ‘guts’ were trying to crawl away. It’s ‘guts’ were actually a mass of tiny maggots. For an instant I thought, “gross, it was pregnant.” But then I realized flies don’t lay live maggots, they lay eggs. [/QUOTE] Your assumption is incorrect. Many flies are ovoviviparous, meaning that the mother retains the eggs inside her body until they hatch. The mother then gives birth to live maggots. ---
**Author:** ![brujaja](https://avatars.discourse-cdn.com/v4/letter/b/4af34b/32.png) [@brujaja](https://boards.straightdope.com/u/brujaja)\ **Post date:** [June 28, 2008, 12:08pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/11 "2008-06-28T12:08:02Z")
Nice of you to pose all that heinous crawly squickiness against a nice bright cheerful orange flower, to sort of take the edge off. Didn’t work, though. GAAAAAAAH! ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [June 28, 2008, 2:08pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/12 "2008-06-28T14:08:57Z")
“Do not click on the link. Do not click on the link . . . Ah, crap.” :smack: ---
**Author:** ![Kalhoun](https://avatars.discourse-cdn.com/v4/letter/k/3bc359/32.png) [@Kalhoun](https://boards.straightdope.com/u/Kalhoun)\ **Post date:** [June 28, 2008, 2:36pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/13 "2008-06-28T14:36:33Z")
EEEEEWWWWW! Here come the nightmares. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [June 28, 2008, 5:13pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/14 "2008-06-28T17:13:44Z")
I didn’t click on the link! NYAH-NYAH! ---
**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 28, 2008, 6:09pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/15 "2008-06-28T18:09:01Z")
[QUOTE=psychonaut] Your assumption is incorrect. Many flies are ovoviviparous, meaning that the mother retains the eggs inside her body until they hatch. The mother then gives birth to live maggots. [/QUOTE] Is there _really_ a word in the English language that has three v’s in it? Cool. ---
**Author:** ![Green\_Cymbeline](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/green_cymbeline/32/9244_2.png) [@Green\_Cymbeline](https://boards.straightdope.com/u/Green_Cymbeline)\ **Post date:** [June 28, 2008, 6:13pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/16 "2008-06-28T18:13:49Z")
I can’t bring myself to open the pics… So did we decide that it was a pregnant fly or what? Since psychonaut informed us that flies can be ovoviviparous? ([Which I had to look up of course…](http://en.wikipedia.org/wiki/Ovoviviparous)) ---
**Author:** ![Terrifel](https://avatars.discourse-cdn.com/v4/letter/t/c68b51/32.png) [@Terrifel](https://boards.straightdope.com/u/Terrifel)\ **Post date:** [June 28, 2008, 6:13pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/17 "2008-06-28T18:13:54Z")
How remarkably fascinating. Plus I learned something new about flies. Those are some keen pictures too. What kind of camera/lens is that? I am now inspired to attempt my own pictures of flies, their wingpit mites, and other small wonders. ---
**Author:** ![shelbo](https://avatars.discourse-cdn.com/v4/letter/s/3d9bf3/32.png) [@shelbo](https://boards.straightdope.com/u/shelbo)\ **Post date:** [June 28, 2008, 8:32pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/18 "2008-06-28T20:32:07Z")
Damn, I guess I need a macro lens. Cool photos. ---
**Author:** ![Fiveroptic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiveroptic/32/8257_2.png) [@Fiveroptic](https://boards.straightdope.com/u/Fiveroptic)\ **Post date:** [June 28, 2008, 8:38pm UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/19 "2008-06-28T20:38:29Z")
Oh my god, I’m horribly disgusted and utterly fascinated at the same time! It’s kind of like reading an eight page Pit trainwreck but without the gossipy voyeurism. I’m not clicking the links. I don’t want to see an eviscerated fly if it was big enough to run a skewer through it. ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [June 29, 2008, 6:34am UTC](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456/20 "2008-06-29T06:34:38Z")
Look at the cricket link. _Look…at…it._ You _KNOW_ you want to. [Next page](https://boards.straightdope.com/t/why-did-this-housefly-have-live-maggots-inside/454456.md?page=2)