# Why do ants touch each other as they pass? **URL:** \ **Category:** Factual Questions\ **Created:** [November 26, 2001, 9:59pm UTC](https://boards.straightdope.com/t/why-do-ants-touch-each-other-as-they-pass/95376 "2001-11-26T21:59:21Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [November 26, 2001, 9:59pm UTC](https://boards.straightdope.com/t/why-do-ants-touch-each-other-as-they-pass/95376/1 "2001-11-26T21:59:21Z")
We have had a continuing problem with ants, and have repelled their invasion as well as we can. But I’d like to know; When I watch ants walking past each other in a trail, they seem to touch each other gently, head-to-head, it seems. Why do they do this? Are they spreading some kind of scent? ---
**Author:** ![UncleBeer](https://avatars.discourse-cdn.com/v4/letter/u/977dab/32.png) [@UncleBeer](https://boards.straightdope.com/u/UncleBeer)\ **Post date:** [November 26, 2001, 10:27pm UTC](https://boards.straightdope.com/t/why-do-ants-touch-each-other-as-they-pass/95376/2 "2001-11-26T22:27:59Z")
I think this is probably better suited to General Questions. I’ll bounce it over there for ya. I hope the ants don’t touch me on the way. ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [November 26, 2001, 10:39pm UTC](https://boards.straightdope.com/t/why-do-ants-touch-each-other-as-they-pass/95376/3 "2001-11-26T22:39:22Z")
…because they can? * * * Okay. They’re communicating by exchanging pheromone signals with each other, which mean things like “yes, I live here, how about yourself?” and “food is over this way”. [http://www.amazinganimalbehavior.com/article1002.html](http://www.amazinganimalbehavior.com/article1002.html) > [@](#): > > The importance of antennae to ant communication is the equivalent of the human voice. Each antenna is multi-jointed, and on the last two segments of each antenna are specialized sensory devices responsible for both tactile and olfactory perception. Hairs covering the last two segments give the ant incredible tactile sensitivity. > > In many ant species, foragers are sent out in search of food, and each scout leaves a trail of scent molecules, or pheromones. When a scout finds food, it returns to the colony so that other members can then follow the trail. Four types of olfactory receptors are located on the antennae, which are critical to pheromonal communication. One type of receptor, tiny depressions containing nerve cells, are so sensitive that a reaction can be triggered by a single pheromone molecule. These same receptors also secrete a mucus-like substance similar to human saliva. Without this substance, an ant would be unable to smell. More info on ant pheromones here. [http://www.conservation.state.mo.us/kids/out-in/2000/02/2.htm](http://www.conservation.state.mo.us/kids/out-in/2000/02/2.htm) ---
**Author:** ![Lao\_Tzu](https://avatars.discourse-cdn.com/v4/letter/l/6f9a4e/32.png) [@Lao\_Tzu](https://boards.straightdope.com/u/Lao_Tzu)\ **Post date:** [November 26, 2001, 11:03pm UTC](https://boards.straightdope.com/t/why-do-ants-touch-each-other-as-they-pass/95376/4 "2001-11-26T23:03:22Z")
Look closely and you will see – they are actually giving each other the High Five. P.S. – to erradicate them, get something called Terro Ant Killer. It’s a boric acid based liquid that they take back to their nest, thus killing off the entire colony. Any time they start setting up a highway into my kitchen, i squirt a couple of drops along their path and within a few days… \* GONE\*. All of them. Only works on sweet-eating ants though. … “…the great, big, real-life natural world we see on The Discovery Channel” – Scott Dickensheets ---
**Author:** ![Ross](https://avatars.discourse-cdn.com/v4/letter/r/e274bd/32.png) [@Ross](https://boards.straightdope.com/u/Ross)\ **Post date:** [November 26, 2001, 11:15pm UTC](https://boards.straightdope.com/t/why-do-ants-touch-each-other-as-they-pass/95376/5 "2001-11-26T23:15:07Z")
That is quite desperately cool. I took a package holiday in the Canary Islands once, and of course my apartment was overrun with cockroaches, with whom I quickly developed a policy of mutual indifference. However I did squish one on a particularly boring evening and spent about three fascinating hours watching a bunch of ants carry all its bits off down a distant crack in the skirting. If I put an obstacle in their way, the next ant along would get confused but figure it out alone till he got back in the loop, and after a couple of minutes the streaming hundreds of ants would all know about the obstacle before they reached it. They were intensely organised. There were little ant foremen, delivery drivers, picketers demanding a bigger cut of the roach, salesmen, travel agents, librarians, performance artists, the lot. Eventually I got curious and gently lifted the skirting board to see where they were going. Imagine my surprise when I found them _reassembling_ my cockroachy nemesis, who looked up darkly and gave me a cold smile. I was back in Scotland before dawn. ---
**Author:** ![Dale\_The\_Bold](https://avatars.discourse-cdn.com/v4/letter/d/41988e/32.png) [@Dale\_The\_Bold](https://boards.straightdope.com/u/Dale_The_Bold)\ **Post date:** [November 27, 2001, 1:14am UTC](https://boards.straightdope.com/t/why-do-ants-touch-each-other-as-they-pass/95376/6 "2001-11-27T01:14:07Z")
Because they just keep going in circles whenever they try to pat each other on the ass.