# Has homosexual behavior ever been observed in invertebrates? **URL:** \ **Category:** Factual Questions\ **Created:** [February 19, 2014, 4:33pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712 "2014-02-19T16:33:07Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [February 19, 2014, 4:33pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/1 "2014-02-19T16:33:07Z")
I know there are gay penguins, and that homosexual behavior has been observed in many other species, but always vertebrate AFAIK. Are there such things as gay insects, arachnids, mollusks, etc.? ---
**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:** [February 19, 2014, 4:56pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/2 "2014-02-19T16:56:44Z")
A lot of invertebrates are simultaneous hermaphrodites, like the [banana slug,](http://scribol.com/news-weird-mating-ritual-banana-slug) and thus I suppose could be considered bisexual. Some male insects and spiders will attempt to mate with other males, but this is almost certainly due to lack of discrimination rather than same-sex attraction. [Bugs not gay, just confused.](http://www.sciencedaily.com/releases/2013/10/131021131009.htm) > [@](#): > > Many species of insects and spiders engage in homosexual behavior, like courting, mounting, and trying to mate with members of the same sex. But it is unclear what role evolution plays in this curious situation. Like heterosexual behavior, it takes time and energy and can be dangerous – and it lacks the potential payoff of procreation. > > Now Dr. Inon Scharf of Tel Aviv University’s Department of Zoology and Dr. Oliver Martin of ETH Zurich have found that homosexual behavior in bugs is probably accidental in most cases. In the rush to produce offspring, bugs do not take much time to inspect their mates’ gender, potentially leading to same-sex mating. > > … > > The researchers say insects and spiders probably have not evolved to be more discriminating in their mating choices because the cost of rejecting an opportunity to mate with a female is greater than that of mistakenly mating with a male. This explanation is supported by the fact that many species that exhibit homosexual behavior also mate with related species or inanimate objects, like beer bottles – indicating a general tendency toward misidentification. ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [February 19, 2014, 5:09pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/3 "2014-02-19T17:09:08Z")
1964 article [Studies on the mating behavior of the house fly, _Musca domestica L._"](https://kb.osu.edu/dspace/bitstream/handle/1811/5017/V64N04_264.pdf;jsessionid=7388856074234B25CF4BE1364DF8F4AF?sequence=1) bears this out: > [@](#): > > […] a “strike” occurs when a male seizes a female at the base of the wings, forcing them out into horizontal flight position, and strives to copulate. […] > > In view of the number of times that males attempt to mate with other males, it seems justifiable to assume that only incomplete sex recognition exists on the part of the male house fly. This assumption is supported by other observations during which males were seen to strike at dead males and females as well as pupal cases lying on the floor of the cage. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [February 19, 2014, 6:05pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/4 "2014-02-19T18:05:16Z")
Of all the papers I read last year, my favorite was the one that showed that if you pull the front legs off of male fruit flies, they can no longer tell the difference between males and females, and so begin attempting to hump every fly they come across. They also lose some ability to distinguish between closely-related fly species, so they will attempt to mate with other species as well. Amputee bisexual flies into bestiality -\> best band name ever. (It goes on to show that there’s a specific neuron in the legs that expresses a specific receptor protein that allows the fly to detect specific pheromones that it uses to make these determinations) ---
**Author:** ![Mississippienne](https://avatars.discourse-cdn.com/v4/letter/m/d2c977/32.png) [@Mississippienne](https://boards.straightdope.com/u/Mississippienne)\ **Post date:** [February 19, 2014, 11:57pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/5 "2014-02-19T23:57:23Z")
I can’t find the video now (but boy, googling “octopi mating” gets some interesting results) but there is footage of two male ocotupuses attempting to mate. Even better, they were of different species. It was interspecies gay octopus humping. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [February 20, 2014, 8:38am UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/6 "2014-02-20T08:38:07Z")
One of my exes was rather spineless . . . . . . . . . ---
**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:** [February 20, 2014, 9:00am UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/7 "2014-02-20T09:00:10Z")
> [@Smeghead](#): > > Amputee bisexual flies into bestiality -\> best band name ever. Amputee Bisexual Flies = Band Name Into Bestiality = Their first album ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [February 20, 2014, 3:52pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/8 "2014-02-20T15:52:53Z")
Oh, and many invertebrates, such as a lot of the gastropods, are hermaphroditic. So they either change sex roles from one mating event to another or mate in both sex roles simultaneously. :eek: 🆒 I’m not sure the concept of a sexual “orientation” is meaningful for invertebrate brains. ---
**Author:** ![garygnu](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garygnu/32/2924_2.png) [@garygnu](https://boards.straightdope.com/u/garygnu)\ **Post date:** [February 20, 2014, 6:59pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/9 "2014-02-20T18:59:00Z")
During the cuttlefish mating season, some smaller males will use their camoflage ability to impersonate females so they can sneak past the large and dominant males that have the real females cornered. I don’t recall hearing of any instances of the larger males trying to mate with the impersonators, so this is just crossdressing, not homosexuality. ---
**Author:** ![Dung\_Beetle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dung_beetle/32/7945_2.png) [@Dung\_Beetle](https://boards.straightdope.com/u/Dung_Beetle)\ **Post date:** [February 20, 2014, 9:27pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/10 "2014-02-20T21:27:17Z")
> [@Colibri](#): > > [Bugs not gay, just confused.](http://www.sciencedaily.com/releases/2013/10/131021131009.htm) Did anyone else hear that in the voice of Mongo? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 20, 2014, 10:40pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/11 "2014-02-20T22:40:56Z")
And then there’s penis fencing, practiced by some flatworms. The worms are hermaphroditic, but in any given mating, one will take on the female role, while the other takes on the male role. Both get the same benefit from this, offspring, but it costs the mother a lot more than it does the father. So how do they decide who gets to be the dad? By penis fencing. The flatworm penis has a sharp point, and they jab at each other until one penetrates the other’s skin and inseminates it. ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [February 20, 2014, 11:07pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/12 "2014-02-20T23:07:15Z")
Different species of nematode are various combinations of hermaphrodite, male, or female. C. elegans are primarily hermaphrodites but there are some males. Their mating behavior is basically to rub their tail on absolutely everything until they find a vulva. Large groups of males will form writhing clusters. If you can excuse the anthropomorphism, they’re probably all thinking “there must be a vulva in here somewhere!” ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [February 21, 2014, 12:13am UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/13 "2014-02-21T00:13:29Z")
> [@Chronos](#): > > penis fencing, Better than a band name, this needs to be a new Olympic sport.😛 ---
**Author:** ![coffeecat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/coffeecat/32/3405_2.png) [@coffeecat](https://boards.straightdope.com/u/coffeecat)\ **Post date:** [February 22, 2014, 2:57pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/14 "2014-02-22T14:57:18Z")
Or a cartoon. Now on sale at Home Depot! ---
**Author:** ![buddha\_david](https://avatars.discourse-cdn.com/v4/letter/b/ee7513/32.png) [@buddha\_david](https://boards.straightdope.com/u/buddha_david)\ **Post date:** [February 22, 2014, 4:01pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/15 "2014-02-22T16:01:26Z")
> [@Colibri](#): > > [Bugs not gay, just confused.](http://www.sciencedaily.com/releases/2013/10/131021131009.htm) Only bugs??? My dog will try and hump my leg when he gets randy. ---
**Author:** ![Siam\_Sam](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Siam\_Sam](https://boards.straightdope.com/u/Siam_Sam)\ **Post date:** [March 4, 2014, 1:34am UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/16 "2014-03-04T01:34:11Z")
> [@Chronos](#): > > penis fencing > [@DrDeth](#): > > Better than a band name, this needs to be a new Olympic sport.😛 Except that cock fights are banned in some countries. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [March 4, 2014, 2:29pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/17 "2014-03-04T14:29:11Z")
> [@Dung\_Beetle](#): > > Did anyone else hear that in the voice of Mongo? You mean Mango? ---
**Author:** ![SpoilerVirgin](https://avatars.discourse-cdn.com/v4/letter/s/4491bb/32.png) [@SpoilerVirgin](https://boards.straightdope.com/u/SpoilerVirgin)\ **Post date:** [March 4, 2014, 5:49pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/18 "2014-03-04T17:49:00Z")
I think he meant [Mongo](http://sportacalypse.files.wordpress.com/2012/10/mongo.jpg) rather than [Mango](http://2.bp.blogspot.com/_fTT9xlgZ9CU/Rzxyap_ZAbI/AAAAAAAABg0/TrhPQOSV-7E/s400/Mango2.bmp). ---
**Author:** ![lance\_strongarm](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@lance\_strongarm](https://boards.straightdope.com/u/lance_strongarm)\ **Post date:** [March 4, 2014, 7:24pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/19 "2014-03-04T19:24:24Z")
Mongo like candy. ---
**Author:** ![IvoryTowerDenizen](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ivorytowerdenizen/32/17937_2.png) [@IvoryTowerDenizen](https://boards.straightdope.com/u/IvoryTowerDenizen)\ **Post date:** [March 4, 2014, 7:37pm UTC](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712/20 "2014-03-04T19:37:16Z")
Since at least the mid-1980s male fruit flies have been shown to court other male fruit flies when carrying certain mutations. Genes that lead to some form of sterility in fruit flies are often given some version of the name “Fruitless”, since they can not bear any offspring. The researcher wanted to name this gene “Fruity”, since males courting males lead to no offspring. :rolleyes: (this rollyeyes does NOT convey how I feel about that name) Not surprisingly, the name was rejected by the drosophila community. Yes, this man was my genetics professor and had the lab next door to the lab I was in as an undergrad. [Next page](https://boards.straightdope.com/t/has-homosexual-behavior-ever-been-observed-in-invertebrates/681712.md?page=2)