This article from Insider gives a brief history of cats on ships, and has a lot of cool photos of maritime moggies. Click to read (excerpted text is indented)
Much of the information comes from Scot Christenson, director of communications for the US Naval Institute and the author of “Cats in the Navy.”
British, French, and Spanish explorers in the late-15th century carried cats to the Americas upon the discovery of the “new world” during the age of exploration.
The animals were so universally revered that local islanders visited by British trading ships would often sneak onboard the ships to try and steal a cat for themselves, Christenson said.
During the Age of Sail, from the mid-16th to the mid-19th century, rats were known to leave an easily-ignitable trail of gunpowder aboard wooden ships as they scurried across the deck, posing a risk to the sailors on board, Christenson said, and cats could help stop the rodents in their tracks.
Even in the modern era, rats and mice remained an inherent danger to many ships, spreading disease, chewing through sails, and eating food supplies, according to Christenson
“But cats are effective predators,” he told Insider.
. . .Cats were considered akin to crew members aboard the British Royal Navy, according to Christenson.
Some sailors would bond so closely with a cat that they would bring the animal home with them at the end of a voyage.
When the US Navy was founded in the 18th century, the military branch borrowed certain customs from its British predecessor, including a penchant for seafaring cats.
Long believed to be powerful and spiritual animals, cats served as omens and portents among early sailors, according to Christenson.
The Japanese believed cats could protect their ships from evil spirits, Christenson told Insider.
Sailors around the globe also believed that a cat’s behavior could predict the outcome of a voyage.
If a cat jumped on board a ship prior to setting sail, seaman believed their vessel would be protected on its journey. But if a cat deserted a boat ahead of its departure, sailors thought themselves doomed, according to Christenson.
The worst sign of all was the sight of two cats fighting on the pier ahead of a sailing, which some sailors interpreted as the devil and angel fighting for their souls, Christenson said.
Sailors initially believed cats were in control of their fate, Christenson said. The animals were thought to have a gale inside their tail because they would begin shaking during storms.
Sailors interpreted this behavior as angry cats calling down foul weather.
Seamen later discovered that moody cats weren’t in fact conjuring storms, instead, they were responding to the physical agitation they felt when the air pressure around them would drop.
Sailors started to watch cats’ mannerisms to detect coming storms.
The animals are also sensitive to high-pitched whines, so cats helped Navy sailors detect coming air crafts during the World Wars, Christenson said.
Budget cuts after World War II dealt a death knell to Navy cats, Christenson said.
Advocates for the financial cuts ridiculed the Navy, accusing the military branch of complaining about a lack of funds while planning birthday parties for their cats.
The public relations aspect of the campaign embarrassed the Navy, even though more often than not, it was the sailors themselves paying for the upkeep of their feline friends.
But it was updated quarantine laws that ultimately led to the end of cats’ seafaring days, according to Christenson.
For years, Navy cats were granted special permission to forgo most country’s standard laws that required incoming private citizens to quarantine their accompanying cats and other pets for several months.
But as nations began cracking down on animal quarantine laws in the aftermath of World War II, ship captains faced serious repercussions if one of their boat’s felines escaped and went exploring in a port city, Christenson said, leading to the demise of the practice altogether.
And a story:
Christenson spent years collecting stories of the cats who served in the Navy.
Of all the cases he found, his favorite anecdote is the tale of “Mis Hap.”
Mis Hap was a tiny kitten found by a Marine [Frank Praytor] during the Korea War, Christenson told Insider. The animal had just been orphaned, and her human rescuer named her Mis Hap because she had “been born in the wrong place at the wrong time.”
The Marine was photographed feeding the cat with a medicine dropper in a heartrending photo that was picked up by dozens of newspapers around the globe, according to Christenson.
Prior to Mis Hap’s discovery, the Marine in question was at risk of being court-martialed after submitting one of his own photographs of wounded Marines to a photo contest, flouting military censors that had banned the publication of such content at the time.
But the marine’s newfound newspaper fame ultimately spared him from the charges and yielded hundreds of marriage proposals from women across the country who were moved by his tender care toward Mis Hap, according to Christenson.
Mis Map went on to become the mascot of headquarters in Korea.
Her Marine eventually brought her back to Chicago where she lived a long, happy life.
A video of Mis Hap and her marine. The story has a twist to it (but no worries: the cat was fine):
This is indeed a photo of Mis Hap and Frank Praytor. He became famous for this photograph:
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A liquid is traditionally defined as a material that adapts its shape to fit a container. Yet under certain conditions, cats seem to fit this definition. This somewhat paradoxical observation emerged on the web a few years ago and joined the long list of internet memes involving our feline friends. When I first saw this question it made me laugh, and then think. I decided to reformulate it to illustrate some problems at the heart of rheology, the study of the deformations and flows of matter. My study on the rheology of cats won the 2017 Ig Nobel Prize in Physics.
The prizes are awarded every year by Improbable Research, an organization devoted to science and humor. The goal is to highlight scientific studies that first make people laugh, then think. A ceremony is held every year at Harvard University

At the center of the definition of a liquid is an action: A material must be able to modify its form to fit within a container. The action must also have a characteristic duration. In rheology this is called the relaxation time. Determining if something is liquid depends on whether it’s observed over a time period that’s shorter or longer than the relaxation time.
If we take cats as our example, the fact is that they can adapt their shape to their container if we give them enough time. Cats are thus liquid if we give them the time to become liquid. In rheology, the state of a material is not really a fixed property – what must be measured is the relaxation time. What is its value and on what does it depend? For example, does the relaxation time of a cat vary with its age? (In rheology we speak of thixotropy.)
Could the type of container be a factor? (In rheology this is studied in “wetting” problems.) Or does it vary with the cat’s degree of stress? (One speaks of “shear thickening” if the relaxation time increases with stress, or “shear thinning” if the opposite is true.) Of course, we mean stress in the mechanical sense rather than emotional, but the two meanings may overlap in some cases.
What cats show clearly is that determining the state of a material requires comparing two time periods: the relaxation time and the experimental time, which is the time elapsed since the onset of deformation initiated by the container. For instance, it may be the time elapsed since the cat stepped into a sink. Conventionally, one divides the relaxation time by the experimental time, and if the result is more than 1, the material is relatively solid; if the result is lower than 1, the material is relatively liquid.
And the answer: Yes, under some circumstances cats are indeed liquids.
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This piece from Gizmodo tells you the best way to summon a strange cat, either outdoors or at a friend’s house. Click to read:
An excerpt:
The study was conducted by researchers at Paris Nanterre University’s Laboratory of Compared Ethology and Cognition, led by Charlotte de Mouzon. De Mouzon has been studying the ins-and-outs of cat-human interaction for several years now. Last October, for instance, she and her team published a paper suggesting that pet cats can readily distinguish their owner’s voice from that of a stranger’s and can also often tell when their owner is directly speaking to them.
. . .For this latest research, published Wednesday in the journal Animals, she wanted to get a better sense of how cats respond to our different modes of communication, both alone and when interwoven with each other.
“When we communicate with them, what is more important to them? Is it the visual cues or the vocal cues? That was the starting question of our research,” de Mouzon told Gizmodo.
They recruited help from 12 cats living at a cat cafe. The experimenter (de Mouzon herself) first got the cats used to her presence. Then she put them through different scenarios. The cats would enter a room and then de Mouzon interacted with them in one of four ways: She called out to them but made no gestures toward them otherwise, like extending out her hand; she gestured toward them but didn’t vocalize; she both vocalized and gestured toward them; and, in the fourth, control condition, she did neither.
THE ANSWER:
The cats approached de Mouzon the fastest when she used both vocal and visual cues to catcall them, compared to the control condition—a finding that wasn’t too unexpected. But the team was surprised by the fact that the cats responded quicker to the visual cues alone than they did to the vocal cues. De Mouzon points out that owners routinely love to adopt a “cat talk voice” with their pets, so they figured that cafe cats would respond better to vocalizations. They now theorize that this preference might be different for cats interacting with human strangers than it would be for their owners.
So, when calling out to a strange cat on the street (something I do EVERY time I get near an outdoor cat), extend your hand and call to them in a soft baby voice.
Langiappe from France (be sure to click the links):
A separate key lesson learned from this research is that French people seem to have their own unique way of getting cats to notice them. The paper details de Mouzon using “a sort of ‘pff pff’ sound” as her vocal cue, which is apparently widely used by people in France to call cats. When she demonstrated the gesture over Zoom, it sounded like a “kissy” sound, at least to this reporter’s ear. And importantly, it was subtly distinct from the “pspsps” sound that’s common among English-speakers trying to attract a cat.
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Lagniappe: Jared Leto as Choupette (the late Karl Lagerfeld’s beloved still-living cat) at the Met Gala:
h/t: Bill, Ginger K., Thomas
Thanks to you, I learned a lot today!
Cats in the Navy looks like a nice read. I miss the cats that used to live at the corner stores (dairies, where I grew up). They were there for rodent control. I think they were outlawed because animals + food stuffs weren’t supposed to mix. (Someone should drop the mice a note.)
I have a very similar picture of my ginger cat Ryzhy acting as a liquid: https://hxstem.substack.com/p/chemistry-with-cats
Even the sink and the faucet look the same!
Excellent collection of facts, stories, and anecdotes! Frank Praytor’s story is heartwarming—as is the compassion shown by his superiors.
Wonderful post!
The photo of the petty officer cradling the cat [Edit: Oops. Cats.] could be a Norman Rockwell painting. The cat walking along the gun barrel of HMS Queen Elizabeth is the more amazing given that it’s a smooth cylinder with no flat spot.
Ships’ cats would be a good topic for Youtuber naval historian Drachinifel to cover. He’s done one on a d*g that got taken into Royal Navy service in South Africa so that the railway conductors couldn’t kick him off the trains, RN sailors being guaranteed free passage between the naval base and the town. I don’t think he drew sea duty though. He was a big Lab.
Continuing my cat conversion therapy.
Ha, should have guessed. Drach has done a video on ships’ cats.
https://www.youtube.com/watch?v=M7HIY0GTEC8
He has a PCC(E)-like affection for moggies.
The definition of “liquid” has been fudged so as to encompass cats. Actually, a cat does not flow downhill, nor does its surface level out.
The US Navy had ~2,000 vessels at the time of the WWI Armistice. With hundreds of thousands of cats scooped up, that would be ~100 per vessel. Less of course for washouts, lost ships, etc.
Sparkies of my acquaintance who have worked on both offshore installations, and mobile vessels would (have, to me, several sparkies, several occasions) argue that “ships cats” are now a positive danger to people and materiel due to their habit of chewing on the insulation for wiring. Of course, rats do the same too, but nobody proposes deliberately bringing rats on board.
I’m afraid the days of the cat on a commercial vessel are long gone. Private vessels – yep they’re still there. Until the owner gets hit with a quarantine fine, which in the UK used to (1990s) start at £1000 and go upwards – since animals travelling on private boats were considered one of the serious threats of rabies entering the UK.