Scientists discover how falling cats almost always make perfect landings

When cats fall, they usually land on their feet. This uncanny ability to right themselves before hitting the ground has long puzzled people. Now, a research team has the answer, and it's all down to the thoracic spine being more flexible than the lumbar spine, as they detail in a study published in the journal The Anatomical Record.

The air-righting reflex is a complex maneuver that protects cats from serious injury if they fall. As they tumble, the spine twists, which seems to contradict the laws of physics. That's because an object in midair shouldn't be able to turn without something to push against.

To find out how they do it, the researchers first studied the spines of five cat cadavers. They separated the thoracic spine (upper/middle back) from the lumbar spine (lower back) and mechanically tested them under twisting forces to measure flexibility, strength and resistance to rotation. This revealed the capability of a cat's body.

The team also used high-speed cameras to film two healthy cats as they dropped onto a soft cushion. They placed markers on their shoulders and hips to track the movement of their body parts.

The team discovered that the cat's spine is not uniformly flexible. Different parts move in different ways to help the animal land safely. The thoracic spine is incredibly flexible and has a neutral zone, a range where it can twist almost freely for nearly 50 degrees with very little effort. Meanwhile, the lumbar spine is much stiffer and acts as a stabilizer.

During air-righting, the cat rotates its head and front legs toward the ground first because the thoracic spine is flexible and the front of the body is lighter. Then the back half follows. The stiff lumbar spine acts as a solid anchor, allowing the cat to whip its front around without spinning out of control.

These results suggest that trunk rotation during air-righting in cats occurs sequentially, with the anterior trunk rotating first, followed by the posterior trunk, and that their flexible thoracic spine and rigid lumbar spine in axial torsion are suited for this behaviour," commented the study authors in their paper.

Yasuo Higurashi et al, Torsional flexibility of the thoracic spine is superior to that of the lumbar spine in cats: Implications for the falling cat problem, The Anatomical Record (2026). DOI: 10.1002/ar.70165

Why lethal mutations persist: Fruit fly study points to newly transferred jumping genes, not small DNA errors
Lethal mutations in wild fruit flies are primarily caused by recently transferred transposable elements, rather than small DNA errors. These jumping genes can rapidly increase mutation rates, temporarily outpacing natural selection until host genomes evolve defenses. This mechanism influences genetic health and persistence of harmful mutations in populations, with implications for conservation and human disease.

Transposable elements contribute substantially to naturally occurring genetic lethality in Drosophila melanogaster, PLOS Biology (2026). DOI: 10.1371/journal.pbio.3003467

Antibiotic resistance can vary depending on where the bacteria live

New research  indicates that the outcome of a resistance measurement may depend on the conditions under which the bacterium is tested. Standard laboratory tests are carried out under fixed, uniform conditions, but if, for example, the test environment is altered, the very same bacterium may in some cases be either more or less susceptible to an antibiotic than the laboratory result indicates.
When doctors or veterinarians receive a laboratory report stating whether a bacterial sample is resistant to an antibiotic, the answer will typically be that the bacterium is susceptible (and can therefore be treated with antibiotics), or that it is not. That answer is correct for the standardized test conditions laboratories use, and it is this standardization that allows results to be compared across laboratories.

However, standard conditions do not necessarily reflect all the environments bacteria encounter in real life. In the body (and across different hosts), factors such as pH level (how acidic or alkaline an environment is) and temperature can vary, and this may influence how effectively particular resistance genes function.

Understanding how antimicrobial resistance develops and spreads is crucial, as antibiotic resistance has become an imminent threat to global public health.
In the study, the researchers investigated two widely prevalent resistance genes to determine how levels of resistance changed when pH and temperature were varied under controlled laboratory conditions. Among other measures, they quantified the amount of antibiotic required to kill the bacterium as pH was altered.

The researchers also examined the significance of temperatures comparable to the body temperatures of different hosts. Here, they observed an effect at temperatures corresponding to birds (around 42°C) compared with humans (around 37°C).

If a resistance gene functions better at 42°C than at 37°C (or vice versa), this may affect how readily bacteria carrying the gene survive and spread in birds, and thus the extent to which birds may act as hosts for bacteria with that type of resistance.
Antibiotic resistance in bacteria can vary significantly depending on environmental factors such as pH and temperature. The resistance genes CTX-M-15 and CMY-2 showed different levels of antibiotic susceptibility under varying conditions, with CTX-M-15 being strongest in acidic environments and weaker in alkaline ones. These findings suggest that standard laboratory tests may not fully reflect resistance in real-world settings.
Findings
CTX-M-15 conferred the strongest resistance in acidic conditions and became weaker as the environment became more alkaline.
CMY-2 performed better at more alkaline pH than CTX-M-15.
At more alkaline pH, bacteria carrying CTX-M-15 could, in the experiment, shift from resistant to susceptible.
Temperature also affected the results, which may be relevant when comparing different hosts and environments.

Mikkel Anbo et al, Contrasting pH optima of β-lactamases CTX-M and CMY influence Escherichia coli fitness and resistance ecology, Applied and Environmental Microbiology (2026). DOI: 10.1128/aem.01775-25