Curiosity killed the keyboard. 

The fog comes on little cat feet,” wrote Carl Sandburg. The great poet and historian may merely have been attempting to animate water vapor, but he presciently put his finger on one of modern life’s more vexing problems. Feline feet can indeed induce a fog, as when you return from grabbing a cup of coffee and find that the cat has done a foxtrot all over the computer keyboard. Four furry paws can turn the “Now is the time for all good men” that was left on screen into “Now is the time for all good mennnnnbbbbbbbvcccccccxzzzzzzzzxcvbnm,;/////////ppoooo,” a decidedly less cogent, if more original, thought.

We human beings are not completely without our wiles, though. Faced with this epidemic of cat hacking, a member of our species named Chris Niswander set his mind to cat-proofing computers for the benefit of all humanity. What sparked his thinking, Niswander says, was his sister’s cat, whose footwork crashed a running program and uninstalled some software. “It was kind of impressive,” he said of the cat feat.

Niswander, a 30-year-old software engineer and president of a Tucson soft ware company called BitBoost, ultimately created PawSense, a program that allegedly discriminates between people and cats. Should it decide that a series of strokes was most likely the footwork of a cat, PawSense cuts off further keyboard input until it is absolutely convinced that a person is back in charge. Whatever anthropic endeavor may have been left half-done and unsaved because of an impulsive fridge trip, mail run or bathroom break is thus kept safe from cat curiosity.

How PawSense tells a cat from a person is, like good comedy, mostly a matter of timing. “The difference between human typing and cat typing is not that cats type gibberish,” Niswander notes, because humans also type stuff that looks like gibberish, such as some odd computer language. “The way that you detect cat typing is by analyzing the combinations of key presses and the timings of those key presses in the combinations,” he explains. Were I, a typical human, to describe something I’ve seen, I would type the letters s, a and then w. Were I a cat attempting to share its experience of the world, however, I’d probably press those three letters simultaneously and trigger the software’s alarms. Were I Hunter S. Thompson, I might find that the software stifles my creativity.

I recently tested PawSense, using a borrowed cat named Schrier. The software worked surprisingly well, blocking Schrier from her attempts to improve sketchy works of questionable literary value. Once the software makes its decision that a cat has commandeered the keys, the monitor screen turns gray and boldly warns, “Cat-Like Typing Detected. ”It also runs a choice of incredibly annoying sounds, such as a harmonica, bad operatic song stylings and general hissing that, at least in theory, may drive a cat away from the computer.

A human has two ways to reestablish keyboard dominion. One may type the word “human” to prove that one in fact is one. Or, based on the assumption that a cat cannot manipulate a computer mouse with anything resembling the decapitating dexterity the species exhibits with an actual mammalian mouse, a person can click a bar on screen that reads, “Let me use the computer!” An added benefit of the software is that it may train your average human to be at least a slightly better typist — I triggered the program once when I mashed a bunch of keys typing this story.

Of course, PawSense is but a stopgap. The day is dawning when voice-recognition technology will remove the keyboard from the computer-human interface. Cats may then creep on their silent haunches back to their usual haunts. Such an evolutionary development should open up a new niche: parrots seem destined to be the bane of tomorrow’s computer users, with some future “BeakSense” software presumably designed to monitor obsessive use of the word “cracker.”

—Steve Mirsky

SCIENTIFIC AMERICAN — March 2000 — Page 26


A cat on a keyboardPawSense helps catproof your computer.

When cats walk or climb on your keyboard, they can enter random commands and data, damage your files, and even crash your computer. This can happen whether you are near the computer or have suddenly been called away from it.

PawSense is a software utility that helps protect your computer from cats. It detects and blocks most cat typing, and also trains your cat to stay off the computer keyboard. 

For more information:

Some Frequently Asked Questions About PawSense(TM)

 Q: How can a software utility know if a cat is on my computer?
pawprint patterns on keyboardA: If you carefully measure cat paws, you will find that practically all cat paws are significantly larger than a typical keyboard key. When a cat first places its paw down, the cat's weight plus the momentum of the cat's movement exerts pounds of force on the keyboard, primarily through the cat's paw pads. The cat's paw angles and toe positions also undergo complex changes while the paw lands on the keyboard. This forces key combinations down in a distinctive style of typing which includes unusual timing patterns. Cats' patterns of overall movement in walking or lying down also help make their typing more recognizable.
Q: I have a Macintosh. Do you have a Mac version of PawSense?
A: We don't yet have the Mac version. Please email us at to request a Macintosh version of PawSense, and to ask to be notified when a Mac version becomes available.
Q: Should my computer have a sound card and speakers of some sort for this software to work?
A: Only if you want your computer to make sounds when the cat gets on the keyboard.
Q: My cat is so mellow that no sound ever annoys him/her. Will your software work?
A: Make sure that your speakers are aimed directly at your keyboard, and turn their volume up a bit. PawSense's "Change Settings" window also includes an adjustment to boost the volume for only PawSense sounds. Make sure this is all the way up.

If one particular sound doesn't work well for your cat, you can set PawSense to use different sounds, or even record additional sounds of your own that you've specifically chosen for your cat.

Over time even a mild annoyance consistently applied should encourage your cat to stop walking on the keyboard. In the meantime PawSense's diversion of most cat-style keyboard input should make it harder for your cat to really mess up your computer. But if that isn't good enough, you will just have to return PawSense for a refund.

Q: My cat is deaf. Can you help me?
A: PawSense detects the paws of even deaf cats. Even if a cat is deaf, PawSense blocks cat typing once detected. This makes it harder for the cat to mess up your programs, data files, and operating system.

However, PawSense does not include a miracle cure for deafness.

Q: How do I buy PawSense?
A: We thought you'd never ask! For more information please click here.
Q: Is PawSense patented?
A: PawSense is sufficiently useful, novel, and unobvious that we can patent it. We have already filed some of the paperwork to get a patent, and will keep this page updated as the situation develops.
Q: What about "BabySense?" Babies abuse computer keyboards too!
A: We are looking at that issue right now. BabySense(TM) may be available for sale soon. In the meantime, if you want PawSense to protect your computer from a baby, we suggest:
  1. If your baby bangs away with outstretched or open hands, or with fists, that makes keypress patterns close enough to those of cat paws, so PawSense should work relatively well. If your baby carefully pecks at only one key at a time, PawSense will recognize that your baby is indeed a human. (s/he is, you know.)
  2. Turn off the annoying sounds, or replace them with a non-annoying sound. Babies, like cats, have sensitive hearing in high audible frequencies and you don't want to encourage your baby to dislike computers, do you? I didn't think so. Don't you want your baby to grow up to be a glamorous computer programmer or the next Bill Gates?

You can email to ask to be notified when BabySense becomes available.

Q: How much RAM does PawSense occupy when it is loaded? What about disk space and CPU time?
A: Except while playing a sound (when a cat is detected) PawSense occupies less than 75K of RAM. Even on a computer with only 16 megabytes of RAM, PawSense uses less than 1/200th of that RAM. PawSense does not use any non-system DLLs such as MFC, VBRUN, etc. that cause some programs to take up too much memory. PawSense uses very little time as well: typically less than 1/1000th of the available CPU time. When your computer is busy PawSense somewhat reduces its CPU usage accordingly. An installation of PawSense takes up less than 2 megabytes of hard drive space. While installing it may temporarily use as much as 4 megabytes of hard drive space.

Sounds that annoy cats

If the speakers are close to the keyboard and aimed directly at it, these sounds will annoy most cats when they're on the keyboard. Note also that PawSense includes the option to turn up the volume for only its sounds, which your browser does not do. To hear example sounds, click on the pictures of the musical notes: (These sounds are © Copyright 1999 BitBoost Systems. All Rights Reserved.)

  Most cats dislike the harmonica.       Hissssss!


© Copyright 1999-2000 by Bitboost Systems. All Rights Reserved.
PawSense, CatsOff, Bitboost, and Bitboost Systems are trademarks and/or service marks of Bitboost Systems.
How can I teach my cat to stay off my computer keyboard? How do I keep my cat off my computer keyboard?
Cat typing. Computer cat-astrophes. 
Catproofing your computer, and computer-proofing your cat. Stop your cat from crashing your computer. 
Paw sense is a mispellng of PawSense. But PawSense does enable your computer to sense paws. .