In the early 1900s, scientific attention to animal cognition was focused on the performance of one animal, Clever Hans the horse. His owner, a mathematics teacher, claimed that Hans could perform addition, subtraction, multiplication and work with fractions. Indeed, Hans could answer questions correctly even if his owner was not present, which led an investigative panel to conclude that this was not a case of fraud (NYTimes, 1904; Pfungst, 1911). Several months later a psychologist was able to determine that Hans could not do mathematics, but instead was sensitive to human cues of correct answers (Allen & Bekoff, 1999; Pfungst, 1911). This planted a seed of doubt in psychological explorations of the numerical abilities of non-human animals; however, these doubts have since been challenged again and again! It is clear that while non-human animals’ cognitive abilities are clearly different than those of humans, these differences, to quote Darwin, are “of degree and not of kind."

Numeracy is the broad range of numerical applications used by humans and other animals. At its most basic level, numeracy is expressed in the ability to discriminate between the size, amount or other aspects of quantity of different objects (Devlin, 2000). Quantity discrimination has been studied in animals from fish to birds to primates, and most animals show some level of it. Many studies of numeracy have been done on carnivores, with canines overly represented. It’s time to give the kitties some scientific attention. An amount that they can detect.

“Number sense” could contribute to the survival of cats in many ways, including reproduction (how many female cats are around?), predation (how many mice are over there? how big is that rat compared to this one?), and safety (how many dogs are in that yard?). But yet only two studies of quantity discrimination have been done with cats.

Slide1In 2009, in a study titled Quantity discrimination in felines: A preliminary investigation of the domestic cat (Felis silvestris catus), four domestic cats were tested by presenting them two food bowls with a card above them (see figure). The cards had either two or three dots printed on them. One of the two stimuli indicated a food reinforcement – for two cats the two dots indicated reinforcement, and for the other two cats, the three dots led to food. Cats were able to discriminate between the two stimuli correctly, but their performance dropped to chance when the area of the stimuli was controlled for -- by increasing the size of the two dots to be equivalent to the area of the three dots on the other card.

From a book a love, Paul Leyhausen's Cat Behavior: a cat with six mice.
From a book I love, Paul Leyhausen's Cat Behavior: a cat with six mice.

For a non-foraging, hunting species that usually catches one prey item at a time (unless you’re this cat) size discrimination may be more important than quantity discrimination.




A new study (“More or less: spontaneous quantity discrimination in the domestic cat) by Bánszegi, Urrutia, Szenczi & Hudson was just added to the mix! All cats were tested in their own homes with a preferred wet food item. The cats were deprived of food for several hours before the experiment to ensure motivation. The cat was placed in between and several feet away from two white boards with the food choices hidden under a cover. When each trial began, the choices were uncovered and the cat was allowed to pick a side, and eat the food that was there (the assumption being that untrained cats would naturally prefer the side with more food, especially if they were hungry).

Slide2In the first experiment, cats were given a choice between a different number of 4-g balls of wet food. Each cat received two trials each of eight different combinations of choices – small ratios (1 vs 2 food balls, 1 vs 3 food balls, 1 vs 4 food balls, and 2 vs 5 food balls) or large ratios (2 vs 3, 2 vs 4, 3 vs 4 and 3 vs 5 food balls). Seventeen out of 22 cats chose the larger quantity more often than the smaller quantity, and performance was impacted by the ratio – with cats more likely to choose the large quantity when the difference between the two amounts was larger (in other words, it is easier for cats to discriminate between 1 vs 4 than between 2 vs 4).

Experiment two looked at whether cats would choose a larger ball of food over a smaller ball of food. The larger food ball could be 2, 3, 4 or 5 times larger than the other ball. The answer is mostly yes. Eighteen of the 22 cats tended to choose the larger food ball more often than the smaller one, but again performance was impacted by how big the difference was between the two amounts, and when the difference was too big (1 vs 5) the cats actually tended to prefer the smaller amount.

Finally, to see if cats were using their sense of smell to make their choices, the experimenters hid food inside opaque tubes – one side had one food ball, and the other had six food balls - and let the cats “follow their noses.” Turns out the cats’ behavior was random in this condition, suggesting that cats are more likely to use visual cues over olfactory cues in the quantity discrimination task.

Even humans have difficulty discriminating between two amounts when the ratio is close to one.
Even humans have difficulty discriminating between two amounts when the ratio is close to one.

Several studies of quantity discrimination demonstrate a common influence on success: ratio. In general, in both nonhuman and human animals alike, performance on all types of quantity discrimination tasks, is best when the ratio is small, and performance degrades as the ratio approaches one. This ubiquitous effect of ratio follows a principle called Weber’s Law (Brannon, et al., 2009), which states that in order to detect a change in a stimulus, the change required is relative to the stimulus intensity, rather than an absolute amount (in other words, it’s easier to tell the difference between 5 and 10 lbs., than between 105 and 110 lbs., even though the absolute difference between them is the same).

The new study did not control for area, so when taking both studies into account, it appears more likely that cats respond to the overall volume or area as a cue more than any numerical information. So based on the results of these two studies, it seems that to cats, it is more important to find the bigger rat than to find more mice. On the other hand, if that rat is too big, it might just be safest to go for a small one - rather than risking a tangle with a very large rodent that might have very big teeth and claws.


Allen, C., & Bekoff, M. (1999). Species of mind: The philosophy and biology of cognitive ethology: MIT Press.

Bánszegi, O., Urrutia, A., Szenczi, P., & Hudson, R. (2016). More or less: spontaneous quantity discrimination in the domestic cat. Animal Cognition, 1-10.

Berlin's Wonderful Horse: He Can Do Almost Everything but Talk. (1904, September 4, 1904). New York Times.

Brannon, E. M., Cantlon, J. F., Tommasi, L., Peterson, M., & Nadel, L. (2009). A comparative perspective on the origin of numerical thinking. Cognitive biology: Evolutionary and developmental perspectives on mind, brain, and behavior, 191-220.

Clever Hans Again - Expert Commission Decides that the Horse Actually Reasons. (1904, October 2, 1904). New York Times.

Darwin, C. (1982). The Descent of Man. (1871) New York: Modern Library.

Devlin, K. J. (2000). The math gene: How mathematical thinking evolved and why numbers are like gossip: Basic Books London.

Pfungst, O. (1911). Clever Hans:(the horse of Mr. Von Osten.) a contribution to experimental animal and human psychology: Holt, Rinehart and Winston.

Pisa, P., & Agrillo, C. (2009). Quantity discrimination in felines: A preliminary investigation of the domestic cat ( Felis silvestris catus). Journal of Ethology, 27(2), 289-293. doi: 10.1007/s10164-008-0121-0




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If not, now is the perfect time to learn more!

I've joined forces with my dear friend and fellow cat consultant, Ingrid Johnson of Fundamentally Feline to bring you a new web resource: Food Puzzles for Cats!

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We show you how to get started - or how to keep challenging your cat if you already use food puzzles with your cat! We'll be describing and reviewing different types food puzzles and giving you links to DIY projects and videos about food puzzles!

We'll also be on Facebook and Twitter...check us out!

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I'm finally realizing how busy getting a PhD makes you! I'm wrapping up a semi-failed experiment and I'm also about to head to the East Coast for a few days of fun and work in Atlanta, and then off to Melbourne, Florida for the Comparative Cognition Society Conference where I'll be giving a short talk on some of my squirrel research.

But I haven't been too busy to chat with folks about my favorite thing...cats.

wapoI was ABSOLUTELY thrilled to talk with Sadie Dingfelder at the Washington Post about her experience clicker training her cat to sit on her lap. Was the loving response fake because she gave him treats for being loving? NO! I don't know why humans get so hung up on "bribing" cats to do things when we "bribe" humans to do things we want all the time! Alexandra Horowitz also weighs in, just in case you thought dogs were not bribe-able. And why do people treat reinforcing behavior you like as if it were a bad thing?

For the record, I love dark chocolate, especially the Alter Eco Quinoa bar.

tailspetDo you love cat videos? Me too, as long as there are no scary cucumbers. I spoke with Laura Drucker at Tails Pet Magazine about why we love cat videos.




atlasI also spoke with Dan Nosowitz at Atlas Obscura not too long ago about how to talk to your cat (last year I spoke to him about whether squirrels are smart). Some great quotes from my favorite cat scientist, John Bradshaw, as well!



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Dominance: An illusion when it comes to dog-human relationships

domThe always astute John Bradshaw wrote a lovely summary this week as to why trying to assess your relationship with you dog through the lens of a hierarchy is misguided and a possible welfare issue. Read it here!

Could a parrot serve as a witness?

echofascinating story of a parrot who knew too much...while humans have a long history of placing animals on trial, this is a new case questioning whether a talking parrot who had been previously owned by a mob boss could provide court evidence against him.




Prairie Dogs: Cute but deadly

Turns out prairie dogs are top killers of a fellow rodent, the ground squirrel. Although it's not unusual for carnivores to kill other carnivorous species, herbivore-on-herbivore violence is considered rare!

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Eye Candy: Hidden cameras capture beautiful wildlife shots

Just for fun, check out some lovely pics of African wildlife caught by camera traps.



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Appetite for Destruction

Squirrels turn off the lights

Squirrel related power outages were reported in: Greenfield, WI, Danbury, CT, Muncie, IN, Halifax, Nova Scotia, Tulsa, OK, Glenpool, OK, Lee County, TX, Columbia, SC, and Pinewood, Ontario.

But it’s not just squirrels

Other wildlife may be to blame, including possums, racoons and even the occasional bird that gets into a power substation.

Why do they do it?

Attraction to warmth and lack of traffic (which presents less of an obstacle) are factors that lead squirrels to the wires.

Fire starters

A squirrel started a fire in a garage in Traverse City, MI, losing its life in the process; and burned down a home in South Nashville.


Police blotter

breakinA citizen reported a dead squirrel on their porch - was it a gag?

And in Massachussetts, citizens reported a bagel being thrown at their home, a man walking around with an umbrella, and a squirrel in a piano.

In Northport, NY, it turned out that the destruction in a ransacked home was caused by a squirrel who then died in the house. And in Canada, a squirrel broke into a home, and stepped on the remote to turn on the television.

In Chelmsford, MA, a “squirrel problem” was reported - what does that mean?? And in Swampscott, MA, a citizen called the police to report a sick squirrel in her yard (what is going on in Massachusetts?)

In Texas, a woman was accused of stabbing a squirrel by her neighbors. She ran from police, and was eventually arrested.

Last year, a police officer in Tennessee tried to subdue a squirrel trapped in a Dollar General store by shooting at it. He lost his job for discharging his weapon unsafely. He sued to get his name cleared, but the case was dismissed. For the record, he was able to catch the squirrel and release it outside safely.


Hunting corner

Some like their squirrel with a side of green peas and mashed potatoes.

A teen shot himself while squirrel hunting, and a man shot his friend instead of a squirrel

One man shot at a squirrel who was eating bird seed he'd put out for BIRDS NOT SQUIRRELS, and subsequently put a hole in his neighbor’s window instead.

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A squirrel who was impaled with an arrow will survive thanks to a local animal clinic who treated him.

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And in Minnesota, scientists are fitting squirrels with radio collars to determine the impact of hunting on local squirrel populations.











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liliesA message worth repeating: lilies kill cats!
I wrote more about it a few years ago in the Dodo...


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I get by with a little help from...mongooses?

Warthogs in Uganda may find themselves being bitten by ticks. A solution? Lie down and let the mongooses climb on them to snack on said ticks. This type of relationship, where both species benefit, is called a mutualism. Read more here.

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Group living necessitates cleanliness

Some insect species are highly social, while others, even if closely related, are not. Scientists recently compared groups of social and asocial ants, bees, wasps, and termites. The more social species had weaker immune systems, but also tend to demonstrate high levels of hygiene and mutual grooming, which may be essential to their survival.

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Ugly and overlooked



A new study shows that conservation efforts in Australia are typically focused on the "good" (aka cute) species, while those most in need, such as native rodents and bats, are overlooked.


This trend is not specific to Australia, as the Ugly Animal Preservation Society has tried to shed light on this problem for years (their motto: "We can't all be pandas")!



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Bird Brilliance

Birds may use alligators as security guards -- previous studies show that birds that nest near alligator habitat produce more offspring. But a new study also showed that alligators near nesting birds were heartier, suggesting that the nesting birds may "pay" for this security service with a few babies that fall out of the nest...into the alligator's mouth. Read a summary here.

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crowWhy are New Caledonian crows good at some tasks and not others? Is it the nature of the test? Researchers in New Zealand looked at the reasons that primates performed better on "self-control tasks" in a recent study that compared cognition across many species (hey I was one of the many authors of that study!) - could hands and experience with humans have an effect?

Meanwhile, a new paper explores the fact that corvids and parrots show cognitive abilities on par with primates, despite having a VERY different brain structure (which lacks the neocortex that is often considered responsible for "higher functions"). Summary here.


Kitty Corner

Can you talk to your cat?

atlasCommunication with cats: it may not be easy, but you can do it! John Bradshaw and I spoke with Dan Nosowitz at Atlas Obscura about recent studies, training cats, and how well they understand what we are saying to them!




Amazing food puzzle hack!

I love anything to do with food puzzles, and homemade is even better. My friend and fellow cat behavior consultant, Ingrid and Fundamentally Feline, came up with this amazing idea to make a foraging and scratching toy out of a chair. Yes, a chair! Check it out!!!

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Does your dog love you?

We spend a lot of time worrying about whether our pets love us. How would you even prove it? @DogSpies' Julie Hecht contemplates the question, and encourages just living with the answer "probably."

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Fat cats won't stop loving YOU if you put them on a diet

fatcatIf your cat is obese, that is a problem! Pet owners who worry that putting their feline on a diet might turn them into grumpy cat should worry no more. A study found that reducing an overweight cat's calories made them MORE affectionate toward owners. Remember: putting your cat on a diet should be done in concert with your veterinarian.



Cats are part of the family

A new survey of cat welfare in Australia found that most owners consider their cat part of the family, and feel confident in their ability to provide for their cat. However, most cats have not been to the vet for a yearly check-up and other findings suggested that owners are not meeting all of their cat's welfare needs. Nice summary from Zazie Todd on her blog Companion Animal Psychology here!

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I'm all for the celebration of rodents; we just had Squirrel Appreciation day, and now today, we (sort of) celebrate another rodent, the groundhog (who happens to also be a squirrel!). I think it's cute, like everyone else, that somehow people are obsessed with the folklore (originated in the 1800s) that somehow a rodent could see into the future and predict the weather.

On the other hand, in this day and age, where people still question whether evolution is real and if the earth is flat, does Punxatawney Phil just encourage more pseudoscience?



First of all, this is attributing some pretty high cognitive skills to a groundhog. But the headlines are a bit misleading. (1) We won't find out if winter is really over (2) Phil can't actually tell us if winter is over, and (3) at the end of the day, aren't we just measuring if it is cloudy or not?

Okay, groundhogs are really cute. Look at Staten Island Chuck!!


"No shadow means early spring." Actually, no shadow means nothing.

ppAre these rodents even good at predicting the weather? Turns out, no. Their "predictions" are only correct 35-40% of the time. So don't put your mittens away yet.

Finally, I just want folks to be aware that Groundhog Day is not necessarily good for groundhogs (or the people trying to hold them). One year, Bill de Blasio dropped a groundhog, who later died from internal injuries. De Blasio's predecessor, Mayor Bloomburg, was bitten by the groundhog, Chuck, when he tried to pull him out of his hutch.

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So at the end of the day, while Groundhog Day is a great movie, and a cute holiday, it might be helpful to take a step back and think about what kind of message this day sends us about animals and science.

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