# What are these metal things on concrete benches **URL:** \ **Category:** In My Humble Opinion\ **Created:** [December 7, 2025, 8:05pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500 "2025-12-07T20:05:25Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [December 8, 2025, 4:52am UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/21 "2025-12-08T04:52:09Z")
> [@Banksiaman](#): > > And as for accommodating the kids who actually listened to their parents and got out of the house and off their phones for a bit of exercise … [We try to drive them away](https://en.wikipedia.org/wiki/The_Mosquito). > **The Mosquito** or **Mosquito alarm** is a machine used to deter [loitering](https://en.wikipedia.org/wiki/Loitering) by emitting sound at high frequency. In some versions, it is intentionally tuned to be heard primarily by younger people. Nicknamed “[Mosquito](https://en.wikipedia.org/wiki/Mosquito)” for the buzzing sound it plays, the device is marketed as a safety and security tool for preventing youths from congregating in specific areas. ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [December 8, 2025, 4:58am UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/22 "2025-12-08T04:58:51Z")
Does that make them entitled to trash those locations? I think that’s what @bump was talking about. This is a very complicated subject, far too prone to generalizations. But there is enough mental illness and chronic drug use among the homeless to qualify as endemic, and enough trash, feces, drug paraphernalia and generally disgusting outcomes to having homeless people congregating in one area to make negative reactions very understandable. I wish there was more agreement about actual solutions. It takes more than building more homes or providing temporary shelter and drug treatment and outpatient facilities and jobs. It may also take willingness to recognize that people don’t have the right to enshittify their environment. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [December 8, 2025, 5:02am UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/23 "2025-12-08T05:02:39Z")
> [@Roderick\_Femm](#): > > Does that make them entitled to trash those locations? When we give them no choice, yes. Forbidding them access to bathrooms doesn’t force them to stop needing to excrete. The more we lock them out of access to services, the more they _have_ to essentially act like they are camping in a wilderness. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [December 8, 2025, 5:37am UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/24 "2025-12-08T05:37:21Z")
When i lived in nyc, my regular subway station was used as an ad hoc homeless shelter. It had benches all the way down the platform, and fluorescent lights that you could turn off by giving them a little twist. It even had a tap for cold running (potable) water at the very end of the track. And every night, around 11, someone would turn off all the lights except in the area closest to the entrance (helpful labeled the late-night area). And a homeless guy would lie down and sleep on every bench except the three in that lit area. And around 7:30am, a cop would come by and turn the lights back on and poke any of the homeless guys who weren’t getting up to leave on their own. The first time i noticed all the sleepers, it made me nervous. But i don’t recall it ever bring a problem. Yes, the benches smelled a little funky in the morning. (Something i was very aware of when I was pregnant.) But they didn’t leave trash there. No one pooped on the platform. (I think some of them peed off the platform at the very end, but not so anyone would notice in the parts commuters used.) I never heard of any violence there. It seemed like an efficient use of space. NYC had a shortage of homeless shelters, and a lot of people didn’t want to use them, because there were rumors of TB spreading in the tight quarters. I didn’t know where those guys went during the day, but they weren’t using the space when it was in demand. It was non-hostile architecture at its best. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [December 8, 2025, 12:00pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/25 "2025-12-08T12:00:53Z")
Another thing is that the hostile architecture like benches are uncomfortable to sit on. So everyone, not just the homeless, is discouraged from using it. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [December 8, 2025, 12:25pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/26 "2025-12-08T12:25:15Z")
> [@Chronos](#): > > Except that homeless people sleeping on park benches mostly aren’t there at the same time that others would be using it. But that’s not what happens. Unless > [@puzzlegal](#): > > And around 7:30am, a cop would come by and turn the lights back on and poke any of the homeless guys who weren’t getting up to leave on their own. Traditionally / Historically, the ‘tap’ would be with a police baton. A club. ON a related note, a lot of the places used by gay men for anonymous sex have been closed in Melbourne. Since Melbourne is a fairly woke place, no government would ever admit to that. Queenslanders would say something like that, and get pilloried in the Melbourne/Sydney press. Instead, toilets are closed “to provide accessible access” at some later date, which still hasn’t arrived 20 years later. The problem is that local government don’t _wish_ to be in the business of providing venues for anonymous sex, and the police are no longer encouraged to beat up people they find engaging in that activity. So the local government just closes the venues. Hoxtile architecture. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [December 8, 2025, 12:44pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/27 "2025-12-08T12:44:21Z")
And that’s hostile to anyone who needs a toilet for its intended purpose. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [December 8, 2025, 1:11pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/28 "2025-12-08T13:11:53Z")
> [@Dewey\_Finn](#): > > And that’s hostile to anyone who needs a toilet for its intended purpose I remember a while back when some businesses were getting called out for installing toilets meant to be difficult to sit on in order to prevent employees from spending any longer than necessary (ie playing on their phone) sitting there. [![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFT-xw-XRmSk3CKrtwGvdGNFffywo861pAlcrIFzOP-7uuWbVeyjFMhPbxV1_Xhr5RleltoI_S0xpyy2KI4zlhIvuaTHXQC6xHPnyQY4EhL6SjqrC-cr2Iar3Unaw5U0WKNpFHduC1JA/s1600/slanted+toilet.jpg) ](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFT-xw-XRmSk3CKrtwGvdGNFffywo861pAlcrIFzOP-7uuWbVeyjFMhPbxV1_Xhr5RleltoI_S0xpyy2KI4zlhIvuaTHXQC6xHPnyQY4EhL6SjqrC-cr2Iar3Unaw5U0WKNpFHduC1JA/s1600/slanted+toilet.jpg) ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [December 8, 2025, 1:27pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/29 "2025-12-08T13:27:57Z")
> [@Melbourne](#): > > > [@puzzlegal](#): > > > > And around 7:30am, a cop would come by and turn the lights back on and poke any of the homeless guys who weren’t getting up to leave on their own. > > Traditionally / Historically, the ‘tap’ would be with a police baton. A club. And it was. But it wasn’t police bearing the homeless. It was a gentle poke. And usually it wasn’t even that, as most of the guys got up and packed up their stuff before the police officer arrived. I mean, might the police have gotten rough if a homeless guy refused to sit up and stop using the whole bench when the morning rush hour began? Probably. But that wasn’t the norm. And the norm _was_ to allow people to sleep in peace overnight. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 8, 2025, 2:14pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/30 "2025-12-08T14:14:33Z")
At least where I am we seem to have a lot of day sleepers on the benches that are physically compatible. We don’t have the volume of homeless enough to fill them to capacity, put it’s pretty typical to see a park with e.g. 10 benches and 2 have homeless snoozers at noon. ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [December 8, 2025, 2:50pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/31 "2025-12-08T14:50:11Z")
> [@puzzlegal](#): > > And the norm _was_ to allow people to sleep in peace overnight The problem with doing that is word gets around and pretty soon the place is inundated with homeless. This happened to a privately owned parking structure in my jurisdiction. It’s open 24 hours but between 11p and 5a it’s not used much. There were a handful of homeless that would sleep in the lobby during those hours and at about 445a a security guard would go through and wake them up and tell them to leave. The structure management didn’t have a problem with this until all of a sudden there were dozens of them all over the structure. Sleeping, puking, shitting, pissing on the floor, fighting, fornicating in the stairwells. The lobby and elevators started to stink to high heaven. They’d sleep in the elevators and when legitimate customers wanted to use them they wouldn’t move or would threaten them. We were getting called 3 and sometimes 4 times a night to clear them out because they no longer would listen to the security guards that came through there even though the guards were armed to the teeth. It became a nuisance call and the structure owners were advised calls there would take very low priority. They’re working on sealing up the structure so only someone with a ticket or code can get it. It’s going to cost them hundreds of thousands of dollars because they let a few homeless “sleep in peace overnight" rather than throwing them out in the very beginning before the place got a reputation as a haven. ---
**Author:** ![snowthx](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowthx/32/10660_2.png) [@snowthx](https://boards.straightdope.com/u/snowthx)\ **Post date:** [December 8, 2025, 3:10pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/32 "2025-12-08T15:10:20Z")
> [@Der\_Trihs](#): > > **The Mosquito** or **Mosquito alarm** is a machine used to deter [loitering](https://en.wikipedia.org/wiki/Loitering) by emitting sound at high frequency. In some versions, it is intentionally tuned to be heard primarily by younger people. Nicknamed “[Mosquito](https://en.wikipedia.org/wiki/Mosquito)” for the buzzing sound it plays, the device is marketed as a safety and security tool for preventing youths from congregating in specific areas. I remember a story about a convenience store owner needing to dissuade people from hanging around the side of the store littering, drinking, doing drugs, etc. He installed a couple speakers and played musak, classical music, and other “uncool” pop music (e.g. Taylor Swift-like) nonstop on a loop, which drove the offenders away and kept others from loitering. ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [December 8, 2025, 3:37pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/33 "2025-12-08T15:37:19Z")
> [@Der\_Trihs](#): > > Forbidding them access to bathrooms doesn’t force them to stop needing to excrete. This is absolutely true. Which makes it so frustrating to find that giving access to public bathrooms soon makes those bathrooms unusable by anyone who doesn’t absolutely have to use them. I assume this mostly comes from the mentally ill and drug users. The public bathrooms in downtown San Francisco, the ones created in partnership with a French company that I can’t remember the name of, had a self-cleaning feature, where after each use the toilet would withdraw into the wall and be sanitized, and the rest of the bathroom would also be cleaned automatically\*. The mostly-homeless drug users took these over to shoot up and pass out in. Authorities couldn’t figure out a remedy for that, so they closed them to everyone. \*This was maybe 20 years ago, so I am working from memory here. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [December 8, 2025, 3:41pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/34 "2025-12-08T15:41:10Z")
> [@Roderick\_Femm](#): > > The public bathrooms in downtown San Francisco, the ones created in partnership with a French company that I can’t remember the name of, had a self-cleaning feature, where after each use the toilet would withdraw into the wall and be sanitized, and the rest of the bathroom would also be cleaned automatically\*. Probably JCDecaux. [![](https://upload.wikimedia.org/wikipedia/commons/e/e2/Barbarossaplatz%2C_WC-S%C3%A4ule.jpg) ](https://upload.wikimedia.org/wikipedia/commons/e/e2/Barbarossaplatz%2C_WC-S%C3%A4ule.jpg) ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [December 8, 2025, 3:41pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/35 "2025-12-08T15:41:49Z")
Yep, that’s them. ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [December 8, 2025, 3:48pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/36 "2025-12-08T15:48:53Z")
Now that I know the name, I was able to find something about these public toilets. I was wrong about at lease some of them still being closed, they have been re-opened for several years apparently. Now they are going to start being replaced with a newer model that is better in several ways. There are only 25 of them, scattered throughout the city. Some of them are actually going to have attendants to make sure they stay usable. When they were first launched, it cost a quarter to get in. I don’t know if that is still the case. ---
**Author:** ![Mean\_Mr.Mustard](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mean_mr.mustard/32/3865_2.png) [@Mean\_Mr.Mustard](https://boards.straightdope.com/u/Mean_Mr.Mustard)\ **Post date:** [December 8, 2025, 3:52pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/37 "2025-12-08T15:52:11Z")
> [@DrDeth](#): > > The bus shelters are horrible- so the homeless….the public restrooms closed- homeless- the turnstyles coin slots blocks- homeless, etc etc. Geez. What do they expect the homeless to do? Go…_home_? mmm ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [December 8, 2025, 4:00pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/38 "2025-12-08T16:00:51Z")
> [@Chronos](#): > > I could, though, see cutting the end off of a park bench for wheelchair access. Like, if there’s a whole layout of them, in front of an outdoor stage (there’s a setup like that at a park near me). That way, a person in a wheelchair can still sit with their family or friends, without blocking the aisle. There is a park near where I work with an outdoor picnic pavilion; the kind you might rent for a family reunion or a kid’s b-day party. There are IMHO, too many picnic tables under it but two of the tables are wheelchair friendly; the table is full sized, but the bench is shorter on one side to accommodate someone rolling up in a wheelchair just like I would sit at the bench; _except_…they’ve placed them such that they are not wheelchair friendly. One is at the edge where one must roll there in the grass/mud (probably _real_ easy to do after it rains 🙄) instead of the paved concrete while the other one is interior w/o enough room between the tables to roll up to it. **A** for effort; **F** for execution. > [@Der\_Trihs](#): > > They are “entitled” by the fact that they exist, and have to be _somewhere._ And being homeless, they have no choice _but_ to be in those public spaces. They aren’t going to magically vanish because they are inconvenient or unsightly. They can’t be blamed fairly for something they have no choice in. I have read that many homeless don’t like the shelters, between their rules (no pets, sometimes single sex rooms or at least single beds, etc.) & they fear theft of their possessions. I would think it would be safer there than on the streets, but I have to believe the people living it. > [@Dewey\_Finn](#): > > Another thing is that the hostile architecture like benches are uncomfortable to sit on. So everyone, not just the homeless, is discouraged from using it. I’d think an armrest on a park bench would make it more comfortable, not less to sit on, while making it impossible to lie down on. ---
**Author:** ![filmore](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@filmore](https://boards.straightdope.com/u/filmore)\ **Post date:** [December 8, 2025, 4:34pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/39 "2025-12-08T16:34:47Z")
> [@puzzlegal](#): > > The first time i noticed all the sleepers, it made me nervous. But i don’t recall it ever bring a problem. Yes, the benches smelled a little funky in the morning. (Something i was very aware of when I was pregnant.) But they didn’t leave trash there. No one pooped on the platform. (I think some of them peed off the platform at the very end, but not so anyone would notice in the parts commuters used.) I never heard of any violence there. For some reason, the homeless situation in NYC is uniquely better than in other cities. I know they have programs to place homeless in nightly housing, but even when they sleep outside, those places generally don’t get trashed. I would see them sleeping in subways, doorways and parks late at night, but in the day they were generally cleared out and there was little evidence they had been there. If that was the case in other cities, I expect people would be a lot more compassionate towards the homeless population. But in most cities, places where homeless congregate and are allowed to sleep quickly turn into encampments that get trashed out. ---
**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:** [December 8, 2025, 4:38pm UTC](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500/40 "2025-12-08T16:38:42Z")
The idea here is inclusion where the wheelchair user isn’t shunted off to the side. It really makes no sense as hostile architecture. Sure, you can’t sleep on it but you also can’t sleep on two chairs placed in the same locations. Which works just as well for seating and takes just as many concrete mounting connections and doesn’t require you to buy a special pointless back piece. Picnic benches often have a short end for a wheelchair to fit up to the table. More often, I’m seeing them with a middle gap instead so, again, the user doesn’t constantly feel like an afterthought. Edit: Looking further, the missing seat design also allows people using a [rollator walker](https://carex.com/cdn/shop/files/FGA223000000_Hero_04182024_2500x2500_33be408e-3fbb-4464-b921-bfb95aea5098.jpg?v=1744827658) to fit in, use the walker seat and lean against the bench backrest. [Previous page](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500.md?page=1) [Next page](https://boards.straightdope.com/t/what-are-these-metal-things-on-concrete-benches/1025500.md?page=3)