There are some stories that stay with you forever, the big scientific moments that change the course of history. These are not those moments – but we can’t stop thinking about them anyway.

Push my button

Surgeon Stuart Meloy was performing a pain-relief operation on a woman’s spine when she started exclaiming emphatically. “You’re going to have to teach my husband to do that,” the woman said. This inspired Meloy to invent an implant to help women who are unable to achieve orgasms in the usual way. New Scientist broke the news in 2001, sparking a frenzy of worldwide media excitement. But 13 years later, Meloy was still struggling to raise funds for a full clinical trial, and the “orgasmatron” never reached a climax.

Monkey pleasure

We aren’t the only primates capable of coming up with creative ways to pleasure ourselves. In a study of long-tailed macaques (Macaca fascicularis) in Bali, Indonesia, at the University of Lethbridge in Alberta, Canada, and her colleagues filmed hundreds of examples of male and female monkeys using stone tools as sex toys, rubbing or tapping them on their genitals. According to at the University of Western Australia, the Balinese monkeys get plenty of food handouts from humans, and this frees up time for sexual experimentation. But some monkeys in other places have unusual kinks, too: another study reported a wild macaque in Japan rubbing its genitals on the back of a sika deer.

Head transplants

In 2015, surgeon Sergio Canavero announced plans to carry out the first human head transplant, intended to extend the lives of people with muscle and nerve degeneration or widespread cancer. He claimed his technique could overcome technical hurdles, including how to fuse the spinal cord and prevent the body’s immune system from rejecting the head. In the following two years, Canavero published animal experiments supposedly backing up his methods, but other surgeons remained highly sceptical. A human head transplant never did happen, but Canavero has reportedly moved on to an even bolder ambition:

Rats driving

Have you ever wondered if a rat can drive a car? Kelly Lambert at the University of Richmond in Virginia has. She and her colleagues built a tiny car with three copper bars that would steer it left, forward or right. Sure enough, 18 rats learned to drive towards food rewards. They even found it relaxing, as measurements of their stress hormones indicated. Lambert proposed that driving challenges could replace traditional maze tests when using rat models to study neuropsychiatric conditions.

The sniff test

Humans are more similar to rats than we like to think. In a psychology experiment, and his colleagues at the Weizmann Institute of Science in Rehovot, Israel, surreptitiously filmed 153 volunteers. After shaking hands with someone of the same sex, people smelled their shaking hand more than twice as much as they did before the handshake. Puzzlingly, after shaking hands with someone of the opposite sex, people were more likely to sniff their non-shaking hand. The team suspected that humans use chemical signals all the time without being aware of it.

Urine fountains

Communication through scent is, of course, widespread in mammals, but some never-before-seen behaviour in dolphins took biologists by surprise in 2025. While studying Amazon river dolphins (Inia geoffrensis), or botos, in Brazil, Claryana Araújo-Wang at CetAsia Research Group in Ontario, Canada, saw a male “flip his belly up out of the water, expose his penis and then proceed to urinate into the air”, she told New Scientist. They saw dolphins do this a total of 36 times, and most of the time another male was nearby and would pursue the stream of urine. The purpose of this behaviour hasn’t yet been established, but hormones in urine might signal a male’s social position or physical condition, said Araújo-Wang.

Giving the finger

As for human modes of communication, many of us struggle to put our smartphones down – so the last thing we’d want is for them to crawl across the table towards us. Nevertheless, Marc Teyssier at the University of Paris-Saclay in France and his colleagues gave phones this ability in 2018, with a robotic appendage dubbed the MobiLimb. It plugs into a device’s USB port and, for some reason, looks eerily like a human finger, giving it a spooky quality reminiscent of Thing from The Addams Family. The MobiLimb can stroke your wrist, wave, wag like a tail or, most disconcertingly, drag the phone around. Thankfully, the idea hasn’t taken off.

Horror frog

If you find the thought of a phone with a finger horrifying, wait until you hear about the nightmare-inducing hairy frog Trichobatrachus robustus. In 2008, researchers reported that these frogs can break their own bones to produce claws that burst through their skin. at Harvard University’s thought these weapons were for defence, but two years later, that they were used in fights between males – and that the frog’s unusual hairs were a kind of armour to protect its vulnerable parts from sharp claws.

Corpse shrinking

In 1957, when New Scientist was 1 year old, we reported on a new method for shrinking an adult human body to the size of a baby. At an exhibition of inventors in Winnipeg, Canada, the unnamed inventor of this process claimed it would make disposing of dead bodies simpler, as they could be slid into underground tubes and take up less space. The method involved applying high pressure to the corpse and squeezing out fluids so its flesh could be compressed into a mould. “All this is, of course, highly ingenious but it is uncertain why the inventor thinks that his newly proposed form of burial is in any way better than the current and very popular method of cremation,” the writer mused.

Transient anus

We may take it for granted, but the anus, which allows food to pass through the body, was an evolutionary breakthrough, both figuratively and literally. The earliest animals, like jellyfish today, had only one gut opening, where food went in and waste came out. In 2019, scientists discovered that the warty comb jelly (Mnemiopsis leidyi, pictured top) forms an anal opening when it needs to defecate, but it vanishes straight afterwards. This, they suggested, could represent how the anus evolved in the first place.

Fart science

Flatus – gas expelled from the anus – has been a topic of endless fascination for many readers (and journalists). In 2001, we featured the work of Michael Levitt at the Veterans Administration Medical Center in Minneapolis, a leading authority on the subject. He developed a “Toot Trapper” that reduces odours by trapping certain gases using activated charcoal. We also reported on a device for monitoring gas emissions from dogs, used to test dog snacks that were supposed to reduce flatulence. In 2016, researchers in Australia worked out which foods cause the smelliest farts by mixing faeces with different foods. They recommended eating less protein and more slow-release carbohydrates to minimise hydrogen sulphide production. In 2022, at the Mayo Clinic in Rochester, Minnesota, and his colleagues worked out that some poos float because of gas from gut microbes, confirming a hypothesis first put forward by Levitt 50 years earlier.

Brew your own

Even stranger things go on inside some people’s intestines, as we found out in 2019. A 46-year-old man started experiencing unexplained mental fogginess, dizziness and memory loss, and had to give up his job. Later, doctors found high levels of alcohol in his blood when he hadn’t been drinking. Eventually, they realised his gut contained high levels of Saccharomyces cerevisiae – brewer’s yeast – which got him drunk any time he ate a lot of carbohydrates. This rare condition, known as auto brewery syndrome, had been triggered when the man took antibiotics for a thumb injury, which disrupted his gut microbiome. This year, a study reported that another man with this condition fully recovered after getting a transplant of faeces from a healthy donor. Both articles were written by Alice Klein, who we also have to thank for the monkey sex toys, car-driving rats, smelly farts and floating poos. Thanks, Alice!

Men who experience premature ejaculation may be able to improve control and extend intercourse using a smartphone app, according to preliminary results from a small randomised trial.

Premature ejaculation is considered the most common sexual dysfunction among men, estimated to 1 in 3 men. An array of treatment options including drugs such as topical anaesthetics or selective serotonin reuptake inhibitors (SSRIs) can delay ejaculation but must be taken repeatedly and may cause side effects. The pills also have to be taken some time before sex, which takes away from the spontaneity of the act. “The existing medical treatments are not curing the situation,” says at Heidelberg University in Germany.

The app, Melonga, offers men a curriculum designed by psychologists and urologists that combines arousal-awareness training, pelvic floor exercises, mindfulness techniques and cognitive behavioural strategies. Users are taught to recognise the “point of no return” before ejaculation and use breathing, relaxation and start-stop techniques to reduce arousal. Modules also encourage communication with partners and challenge negative thought patterns through cognitive behavioural therapy.

In the , 80 men were randomised to either use the app or receive no structured intervention over an initial 12 weeks. Among the 66 participants who completed the study, those using the app increased their intravaginal ejaculation latency time from an average of 61 seconds to 125 seconds, with results seen after four weeks of use. The control group saw virtually no change.

Men who used the app reported that the benefits extended to a reduced impact on their relationship and improvement in the enjoyment of sex, tied to its longer duration. Premature ejaculation can be caused by prostate or thyroid issues, while it can also overlap with depression, but the inclusion criteria for the study ensured only healthy participants were selected.

Groeben presented the at the European Association of Urology congress in London today.

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“Doctors prescribe pills much more than simple solutions,” says at the University of Catania, Italy, who was not involved in the research. “In 10 or 15 minutes [for an appointment], pills are the easiest solution for the doctor, but not for the patient.” The app, he says, “is like having a doctor on your phone” – giving men and their partners the opportunity to privately “understand their premature ejaculation issue”.

Russo describes the effects of the app, which was developed by Netherlands-based health start-up Prognoix, as “dramatic” – with 22 per cent of participants no longer qualifying for the definition of premature ejaculation after using it. “Improving just 1 or 2 minutes is a big result,” he says.

“One of the reasons patients have premature ejaculation is anxiety,” Russo adds. “Kegel [pelvic floor] exercises and muscle control can help them manage that anxiety and control the reflex.”

A slew of similar apps to combat premature ejaculation already exist, but none have been tested in a controlled study. One advantage of a digital approach is discretion. “A lot of patients don’t go to see their doctor about this condition because they feel a stigmatising effect when they sit in the waiting room with other patients,” says Groeben.

Same-sex sexual behaviour may help monkeys and apes rise up the social ranks and ultimately have more offspring – and it seems to be especially beneficial in harsh environments where there are lots of predators, say, or a shortage of food.

That’s the implication of a study looking at why the level of same-sex behaviour varies in different primate species. It supports the idea that, contrary to what is commonly assumed, same-sex sexual behaviours in apes and monkeys are an adaptive trait that boosts survival.

It has often been claimed that same-sex behaviour is somehow “unnatural”. But in addition to people, it has now been reported in at least 1500 animals, from insects and dolphins to bison and bonobos.

There are many reasons to think this is the tip of the iceberg. Most species haven’t been closely studied; same-sex behaviours often aren’t recognised when seen because the sexes of the individuals involved may not be clear; and even when such behaviours are recognised they may not be reported.

Of the 20 or so mammal species that have been closely studied over long periods, same-sex behaviour has been . In a colony of rhesus macaques (Macaca mulatta) on the Puerto Rican island of Cayo Santiago that has been studied for many decades, for instance, three-quarters of males engage in same-sex behaviour, at Imperial College London and his colleagues reported in 2023.

In other words, there can now be no doubt that same-sex behaviour is entirely natural. The question is why?

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This has sometimes been referred to as “the Darwinian paradox”, because of the common assumption that homosexual behaviour is non-adaptive – that is, that it doesn’t help individuals have more offspring, or boost the survival chances of those they do have.

Various explanations have been proposed for why same-sex behaviour is so common if it is non-adaptive. One is that same-sex behaviour occurs , that is, because individuals can’t tell the difference between males and females. This is probably true of simple animals such as insects, but it’s certainly not the case for highly intelligent animals such as apes and dolphins.

Another is that it’s a side effect of selection for other traits. For instance, it has been suggested that some traits that boost reproductive success in women may be linked to a greater likelihood of homosexuality in men.

It’s also possible that same-sex behaviour is adaptive, after all. One idea is that it helps males build coalitions that ultimately give them more access to more females. “Same-sex behaviour is, if you want, a currency that you can use to navigate your way in these societies,” says Savolainen.

His team has now analysed data on the prevalence of same-sex behaviour in 59 primate species and looked for associations with environmental and social factors. Among other things, they found that it was more likely to occur in drier environments where food was scarce or where there was more predation pressure, as well as in more complex societies.

For a behaviour to become more common in stressful environments does suggest it is adaptive. If, say, same-sex behaviour was done for pleasure only, you’d expect it to be less common in stressful environments.

“Same-sex behaviour may facilitate better cooperation and cohesion by strengthening social bonds, which is particularly important in these stressful environments,” says team member , also at Imperial.

“But to demonstrate adaptive value, the behaviour needs to be linked to increased fitness, that is, a higher number of offspring,” says Savolainen. “This is precisely what I intend to test in macaques.”

So we are not yet at the point where we can conclusively say same-sex behaviour in at least some primates is adaptive, but it could be that science is about to turn yet another of our preconceptions about this behaviour on its head.

What does this tell us about homosexual behaviours in people? Well, if these findings are confirmed, it might help explain why it is as common as it is. What it does not tell us, the researchers stress, is anything about the rights or wrongs of such behaviour – this is the so-called naturalistic fallacy. That is, human behaviours should not be judged based on what animals do.

That said, there is a certain delicious irony in the idea that when it comes to the survival of the fittest, we may need to redefine who the fittest really are.