Purring occurs as a result of vibration of vocal cords due to neurological stimulation from brain activity. The purpose of purring is uncertain but it does seem to be associated with pleasurable activity. However, cats are also known to purr when ill or injured, which lead some to believe that the frequency of the vibration of the vocal cords can be associated with greater healing. Purring also is reinforcing for people when they are petting cats and therefore can act to increase the amount of petting. —John Ciribassi, DVM, DACVB

Cats generally purr when in contact with someone; a favored owner stroking, nursing a kitten, or greeting a familiar partner-cat. Positive experiences also elicit purring, rolling or rubbing, being in a warm familiar environment or about to fall peacefully asleep. —Elizabeth Colleran, DVM, DAVBP (feline practice)

Average life span in cats is around 15 years of age. However, this can vary widely depending on the health of the cat, nutrition and preventative care. We have had cats in our practice live to 22 years. —John Ciribassi, DVM, DACVB

Like so any things in life, it depends. Lifestyle: Outdoor cats often live shorter lives than indoor. Being overweight or obese shortens life by 1 to 2.5 years on average. Regular health care, physical examinations, parasite prevention and vaccinations provide protection against threats to life and health. —Elizabeth Colleran, DVM, DAVBP (feline practice)

Today’s house cats can expect to live 15 to 20 years, with some reaching 22 to 25. Advances in preventing kitten-hood diseases such as distemper and Feline leukemia, parasites, heartworms, and better diets are key in extending longevity. In addition, indoor cats living today face fewer threats from predators and trauma. Sadly, indoor cats also are facing an obesity epidemic leading to skyrocketing rates of diabetes. —Ernie Ward, DVM

Kneading behavior in cats is a reflection of instinctual behavior from the time of kittenhood. Kittens knead the mammary glands of the queen as a means of stimulating milk production (milk “let down”) through the release of oxytocin. I see this in older kittens and cats when they are content and are attempting to solicit attention. —John Ciribassi, DVM, DACVB

Cats knead for two reasons. While settling down to rest, some cats will knead soft places as if to prepare it to lie comfortably. This may be from a time when vegetation would be knocked down to make a safe sleeping place. Kittens knead the queen to help with milk release when they are nursing. Kneading always seems to happen when the cat is comfortable. —Elizabeth Colleran, DVM, DAVBP (feline practice)

While we don’t fully understand why cats knead, veterinarians have a few theories. One theory is kneading cats are marking territory with special scent glands located in the paws. Another is that kneading is a lingering behavior from suckling. Finally kneading may be a form of stretching or it just plain feels good. —Ernie Ward, DVM

Often they appear to be asleep but are instantly awakened, this type of sleep varies with another deeper one. They tend to sleep in short increments of 10 to 30 minutes, so they are probably not sleeping as much as we think. —Elizabeth Colleran, DVM, DAVBP (feline practice)

They are very sensitive sense organs and tell a cat a lot about his position in space and what is going on around him. They appear to be particularly useful in low light and darkness, times when other organs cannot collect as much information. —Elizabeth Colleran, DVM, DAVBP (feline practice)

Catnip is an herb. Some say it is related to mint, oregano or basil. About half of cats are genetically likely to respond to the effect of the active oil in catnip,nepetalactone. It is not certain what part of the brain is stimulated by this ingredient but it is not harmful to the cat and can be used to help increase use of items like scratching posts or facial marking combs. Many treats have this to help stimulate play. —John Ciribassi, DVM, DACVB

The aroma of catnip in cats is thought to be quite pleasurable. It has no other significance and seems to be a genetic accident. It is an autosomal dominant trait, so not all cats are sensitive. —Elizabeth Colleran, DVM, DAVBP (feline practice)

Not all do. There are many types and breeds of cats that are comfortable around or in water. Many cats will fish for food. The Turkish Van and Maine Coon seem to like water—even being immersed in it. For those that don’t like it, it may be related to the way their fur is constructed. It isn’t made for drenching and can become quite heavy when it is. —Elizabeth Colleran, DVM, DAVBP (feline practice)

For cats that eat grass, it seems not to be associated with illness or dietary deficiency. One theory is that it is an evolutionary adaption to intestinal parasites and may serve as a purging mechanism. The taste of sweet moist grass may help to explain it as well as there are some observers who think it is more common with new spring grass. —Elizabeth Colleran, DVM, DAVBP (feline practice)

The short answer is we don’t know. Most veterinarians agree grass eating seems to be a way for cat to relieve gastrointestinal (GI) symptoms, parasites or possibly infections. Another theory is that cats are craving micronutrients found in leafy plants. Finally, cats may eat grass simply because they like it. It’s important to remember some cats suffering from inflammatory bowel disease (IBD) may be misdiagnosed as “grass eaters” when the real problem lies within. If your cat is eating grass everyday or large amounts, ask your vet to check out your cat immediately. —Ernie Ward, DVM

Cats like to hide and yet be able to see what is going on around them. A box is a perfect place to do that. The opening gives them the view and the sides of the box can protect them from being seen by predators. Remember cats are today the same cats they were 10,000 years ago when they hunted and avoided predators to survive. —Elizabeth Colleran, DVM, DAVBP (feline practice)

They are called a clowder or a glaring. —John Ciribassi, DVM, DACVB

A group of cats is a clowder. A group of related kittens is a litter. A few litters are a kindle. —Elizabeth Colleran, DVM, DAVBP (feline practice)

A group of cats is called a “clowder.” Clowder originates in Middle English from the term “clotter,” which meant, “to huddle together.” It also has roots in “clutter” which is what my clowder creates in my house.