Locusts are known for their massive swarms, in which they devour crops and can destroy enough food to feed 35,000 people in one day. They are also cannibals, so huge swarms present a danger to the insects themselves 鈥� but researchers have found that migratory locusts produce a pheromone that throws their swarm-mates off their scent.

In the animal kingdom, cannibalism is pretty run-of-the-mill. 鈥淣ot eating [members of your species] is a human invention,鈥� says at the Max Planck Institute for Chemical Ecology in Germany. 鈥淚t鈥檚 a loss of energy to not eat whatever is around.鈥�

Recently, scientists determined that cannibalism helps drive locusts鈥� apocalyptic swarms. 鈥淭hey actually start eating each other from behind,鈥� says Hansson. 鈥淵ou have to start moving, otherwise the guys from behind will eat you.鈥�

Cannibalism even drives swarms in flightless juveniles, says at Max Planck Institute of Animal Behavior in Germany. 鈥淚f swarms take flight they become even harder to control. It鈥檚 somewhat like a wildfire,鈥� he says.

Hansson and his colleagues hypothesised that locusts must have evolved countermeasures to deter their neighbour from eating them when they gather in large groups. The researchers began by looking for odour compounds produced exclusively by juvenile locusts (Locusta migratoria) under crowded cage conditions of up to 250 individuals per cage. Using a technique called gas chromatography that separates out the different chemical compounds in a sample, they identified 17 compounds the locusts produced, including phenylacetonitrile (PAN). PAN was already known to deter other species such as birds, because it can be converted into a toxic cyanide compound.

To test if PAN protects against cannibalism in juvenile locusts, the researchers used CRISPR gene editing to create a line locusts that lacked the gene for PAN. These insects then quickly became the targets of cannibalism. In another line of locusts, the researchers disabled the olfactory receptor that detects PAN. This drove the locusts to begin eating any neighbour, even those producing the deterrent odour.

The findings could one day be used to help manage locust swarms, decreasing their numbers without need for current approaches like pesticides. at Texas A&M University says that in principle, blocking the locusts鈥� ability 鈥渢o either produce or detect the pheromone has the potential to cause the locust populations to self-regulate by eating themselves鈥�. It could also make locusts more vulnerable to other predators.

Monogamous prairie voles lacking receptors for the 鈥渓ove hormone鈥� oxytocin still bond with their mates and their young 鈥� contradicting long-held assumptions about how essential the hormone is for these behaviours.

Also known as the 鈥渃uddle chemical鈥�, oxytocin is released in our brains during moments of romantic intimacy, parenting and other forms of social bonding, as well as during labour and lactation. 女生小视频s have spent decades studying the hormone鈥檚 role in the brains of many mammal species, including the prairie vole (Microtus ochrogaster). These voles have been particularly interesting to researchers because, unlike other laboratory animals such as mice and rats, prairie voles show intense attachment to one long-term partner, a behaviour called pair bonding.

For decades, pharmacological studies suggested that oxytocin receptors 鈥� the proteins studding the outside of cells where oxytocin molecules attach 鈥� were essential to produce bonding behaviours. So when at the University of California San Francisco and his colleagues removed oxytocin receptors in prairie voles by using the CRISPR gene editing technique, they were shocked to find that the animals still pair bond.

Manoli still remembers the moment co-author Kristen Berendzen walked into the lab to tell him the news. 鈥淲e were floored,鈥� he recalls.

Prairie voles lacking oxytocin receptors were also able to give birth and nurse their young, spending long periods of time grooming and huddling with them. The voles behaved very much like prairie voles that still had their oxytocin receptors intact.

However, vole pups born to mothers lacking oxytocin receptors weighed significantly less by the time they reached weaning age, suggesting that the mother had issues with milk production or nursing. They were also less likely to survive to weaning age. So, although pair bonding and other important social behaviours were not impacted, oxytocin receptors still seemed to play a substantial role in vole pup development.

鈥淲hat I love about this paper is that, yes, it鈥檚 looking at partner preference in particular, but there are also these major questions about childbirth and child rearing,鈥� says at New York University Grossman School of Medicine. 鈥淭hese fundamental processes of birth and nursing that make us mammals are so woefully understood.鈥�

Manoli says that, once the initial shock wore off, the findings made more sense.

鈥淚t鈥檚 not surprising that there isn鈥檛 a single point of failure for behaviours as important to a species as attachment,鈥� he says. A more complex system could also explain the failure of of oxytocin in people with social anxiety disorder, schizophrenia and other conditions. Such trials aimed to alleviate issues people were experiencing forming social attachments and appropriately processing social situations.

鈥淲hen the implications from pharmacology first came out, there was this hope that oxytocin could be a major therapeutic intervention,鈥� says Manoli. But the trials yielded inconsistent results with no dramatic patient improvements in social behaviours. It could be that oxytocin is just one part of a hormonal mosaic behind bonding.

Manoli and his colleagues are considering what chemical processes in the brain might be compensating in the absence of oxytocin receptors, or if oxytocin might even be binding to other receptors in the brain to make crucial social attachments possible.

Zuul, destroyer of shins, was a living tank. This dinosaur鈥檚 spine and tail were covered in armoured plates studded with spikes, ending in a club previously thought to be used to fight off vicious predators like the Tyrannosaurus rex. But a rare fleshy fossil suggests these armoured herbivores probably used their tails less to fend off T. rex and more to dominate each other.

Zuul 肠谤耻谤颈惫补蝉迟补迟辞谤鈥檚 name comes from the demonic Zuul from the 1984 film Ghostbusters, with crurivastator meaning 鈥渄estroyer of shins鈥�. Its fossil was discovered nearly a decade ago 鈥� during a dig in Montana to unearth a Gorgosaurus, an earlier cousin of T. rex 鈥� when excavators bumped into the dinosaur鈥檚 tail club. Years later, when researchers at the Royal Ontario Museum in Toronto were preparing the fossil for exhibition, they found that some of the fossil鈥檚 spikes were damaged. Many of these had smooth areas indicating the bone had reformed, and some had growths of keratin 鈥� both signs of healing, suggesting injuries on multiple occasions.

鈥淭he [damaged spikes] are just in this little range around the hips, and just on the sides of the body,鈥� says at the Royal BC Museum in British Columbia. They鈥檙e not broken on the top of the body or up by the head, which is where you鈥檇 expect a predator like T. rex to attack, she says.

鈥淏ig, predatory dinosaurs can bite with enough force to leave scratches and puncture marks on bone,鈥� says Arbour. But these marks are missing on this fossil.

Based on the damaged spikes being at different stages of healing, and in a location both easily reachable by another Z. 肠谤耻谤颈惫补蝉迟补迟辞谤鈥檚 swinging tail and unlikely to be fatal, the researchers believe the dinosaurs used their tails to fight each other for social dominance. They suspect it was similar to the way modern animals use antlers or other body parts to stake claim to territory or mates. So, although the club-like tail may have come in handy for self-defence, its evolution was probably driven more by sexual selection than predation.

The idea of these dinosaurs using their tail clubs to fight off T. rex had 鈥渂ecome something of a textbook stereotype鈥�, says at the University of Birmingham in the UK. He sees this study as a prime example of how a long-standing hypothesis can be upended with new evidence. 鈥淣ow that palaeontologists know what to look for, the same damage in other, maybe yet-undiscovered, fossils could come to light,鈥� he says.

Bats are known for their high-frequency calls, which they use to echolocate and catch prey, but they also let out much lower frequency calls for bat-to-bat communication. The structure in a bat鈥檚 larynx that lets them produce these sounds is the same one used by death metal singers to growl out low notes.

For decades, scientists speculated as to which structures in a bat鈥檚 larynx produce different frequencies. 鈥淏ut that was just through anatomical inspection,鈥� says at the University of Colorado Colorado Springs. 鈥淎nd then we went ahead and said, 鈥榃ell, is that actually the case?鈥欌��

H氓kansson and his colleagues affixed individual larynges dissected from Daubenton鈥檚 bats (Myotis daubentonii) with a microphone and placed them under a microscope. They then funnelled air up through the larynx, simulating how it would travel out of a vocalising bat鈥檚 mouth. This airflow caused structures in the larynx to vibrate and produce sound, which the researchers captured with an ultra-high-speed camera. The researchers pinpointed two laryngeal structures responsible for the extreme highs and lows of a bat鈥檚 vocal range, which spans three or four more octaves than the average human鈥檚.

They found that high-frequency echolocation calls are produced by thin, translucent vocal membranes that rest atop the vocal cords. Lower frequency squeaks came from the bats鈥� false vocal folds, which get their name from the fact that 鈥渋n humans they are rarely used, never for speech鈥�, says at the University of Southern Denmark. False vocal folds are, however, believed to be used in extreme vocalisers like death metal grunters. In a way, says Elemans, social squeaks are a bat鈥檚 version of death metal. 鈥淚t鈥檚 a very high frequency sound for us,鈥� he says. 鈥淏ut for them, it鈥檚 extremely low.鈥�

H氓kansson is impressed but not surprised that bats use two distinct structures to make vocalisations that span around seven octaves. 鈥淚t鈥檚 sort of like having one pair of legs for walking and one pair for running,鈥� he says.

at Tel Aviv University in Israel is impressed by the work and would like to see it validated in a living animal, but getting high-speed footage of the inside of a vocalising bat isn鈥檛 currently possible. 鈥淚鈥檓 just waiting for the technology that will allow us to do it,鈥� he says.

Although the average human can鈥檛 compete with a bat, Elemans says the exceptional vocalist shouldn鈥檛 lose hope. For example, Mariah Carey has a five-octave vocal range and is known for being able to sing extremely high tones called whistle notes. 鈥淚f Mariah Carey would be very good at grunting, she could also extend her vocal range even further.鈥�

Sign up for Wild Wild Life, a free monthly newsletter celebrating the diversity and science of animals, plants and Earth鈥檚 other weird and wonderful inhabitants

To escape sexual cannibalism, some animals move stealthily to avoid detection or even play dead 鈥� but male orb-weaving spiders have developed another approach: after copulation, they rapidly catapult to safety. This is the first time catapulting to avoid being eaten by a mate has been reported.

at Hubei University in China and his team first noticed this behaviour while studying orb-weaving spiders in the mountains in Wuhan in October 2019.

The researchers decided to investigate things further in the lab. They used high-speed cameras to capture the behaviour of 155 mating pairs of an orb-weaving spider (Philoponella prominens). Only three of the males didn鈥檛 catapult after mating, and all were promptly captured, killed and eaten by their partners. All of the males that catapulted after mating survived.

To further test the necessity of this behaviour, the researchers put a small paintbrush behind the spiders that blocked the males from catapulting. They, too, were all killed and eaten.

The cameras revealed that the males launch themselves at remarkable speeds of up to 88.2 centimetres per second, which Zhang says is impressive for a spider only around 3 millimetres in length. That is as if a person 183 centimetres tall flung themselves 538 metres 鈥� the length of about five football fields 鈥� in 1 second.

at the State University of New York at Fredonia says this research contributes to our understanding of how sexually cannibalistic species continue to successfully mate. But he wonders if the escape strategy might also be used in response to other threats. 鈥淗ave males co-opted a general anti-predator defence or is this uniquely an adaptation to reduce the risk of sexual cannibalism?鈥�

Zhang and colleagues hypothesise that this behaviour evolved to signal fitness as mates. 鈥淚f a male could not catapult, or the catapulting ability is not good, the female may deplete or eliminate its sperm, and accept other males鈥� courtship and sperm,鈥� says Zhang.

Sign up for Wild Wild Life, a free monthly newsletter celebrating the diversity and science of animals, plants and Earth鈥檚 other weird and wonderful inhabitants