A litter box, sometimes called a "sandbox", "sand box", "litter tray" or "litter pan", is an indoor feces and urine disposal box for cats (as well as rabbits and other pets that naturally or through training will make use of such a repository) that are permitted free roam of a home but who cannot or do not always go outside to relieve themselves.
In the wild, cats naturally excrete in soft or sandy soil, for easy burial. To simulate this instinctively desired type of site and stimulate the natural inclination to hide the excretions, a litter box's bottom is filled typically with an inch or more of litter box filler (frequently called "cat litter" or "kitty litter", though this is a back-formation - the "litter" in "litter box" is actually a euphemism for fecal matter, not for the substrate that pet owners line the box with). Litter box filler is a loose, granular material (most often made of clay, often formulated to clump solidly, though recycled paper "pellet" and silicon based "crystal" variants are also popular options), that absorbs moisture and which meets a cat's instinctive desire to use an easily-dug material. It is advisable to place the litter box on a mat or some newspaper, as the cat will inevitably kick some litter over the edge of the tray when using it and track some of it out of the box, on their paws.
Originally made of wood, the cat box today is most basically represented by a plastic tray with outwardly-sloped sides several inches high. More elaborate models are enclosed, looking rather similar to pet carrying cages with open doorways, providing some allegedly-desired privacy to the pet, and better odor control, as well as keeping the litter out of sight. To facilitate emptying the litter box, plastic liners, similar to garbage bags but much more expensive, are available, though many pet owners do not bother with them.
Recent developments in litter box technology have made further improvements to the emptying procedure. Some models have electric combing mechanisms that automatically scoop the clumps out of the litter box into a sealed, disposable-bag-lined container after the animal has used it. Other models can be shaken to move all of the clumps into an easy-to-remove tray. Another variant has an enclosed sphere which rotates as it sifts out the clumps and deposits them in a drawer below the sphere. A recent variation further automates the litter-emptying procedure with automated scooping and emptying into disposable litter storage cartridges. Many owners do not use these, however, because the sudden automated motion scares their cat(s).
Litter training is one of those areas you much rather have go right the first time. Here's some tips to make the litter box work for you and your cat.
Pick the right litter box for your cat Think about the size and habits of your cat. For instance, a kitten or older cat may do best when they have lower sides to climb over. Household with multiple animals or litter boxes in a trafficked area may find their cat prefers one that is hooded for privacy.
Pick the right spot for the litter box Just like us, cats want a quiet, private place to use the restroom. Highly trafficked areas, areas with other animals or wide open spaces aren't usually the best choices. Find a place your cat will feel comfortable in and easily be able to reach. Kittens and older cats may need the litter box moved to avoid stairs or other obstacles.
Don't overfill the box Two to three inches of litter should be more than enough for your cat to scratch in, but not so much that they're throwing litter out of the box. Again, get to know your cats habits; some may need more or less depending on their style.
Always have a clean litter box Just like your mom obsessed over a clean bathroom, cats will quickly turn down a litter box that's not clean enough for their taste. What may smell clean to us might smell entirely different to a cat's sensitive nose. Optimally, litter boxes should be scooped daily and completed dumped on a regular basis.
Teach new cats the litter box location New cats typically hide while adjusting to a new home. Make sure they are aware of the litter box, even if that means moving it to a place convenient to their chosen hiding spot. As they become more comfortable, you can gradually move the litter box. Kittens may need to be confined to one area as they learn to use the litter box properly.
Have enough litter boxes for everyone If you have more than one cat, you'll need more than one litter box. Cats can be quite territorial and their bathroom habits are no different. Ideally you should have one litter box for each cat. You may need to experiment with placing of multiple litter boxes to make everyone comfortable.