Dogs and cats do many things that seem pretty strange to us humans (and vice-versa). But while we find them weird, many of those behaviors are perfectly healthy for our pets. Others, however, could be a sign that something’s going on with your fur buddy that requires medical attention. Learn more in “Why Does My Pet Do That?” — Volume 2! 1) Why do dogs eat grass? Most people think that dogs only eat grass when they’re not feeling well. While it’s true that dogs do sometimes eat (or — in this case — gulp down) grass to tickle their throat and help them throw up when their stomachs are upset, many dogs also enjoy eating grass because they like the texture and are looking to add a bit of roughage to their diet. Unlike cats who are strictly carnivores, the modern dog enjoys plant matter as well — usually in the form of fruits and veggies, which have become common ingredients in commercial dog foods and are often fed as healthy treats. Fruits, vegetables — and grass — all contain vitamins, minerals, and fiber that are healthy for our pooches. If you have a dog who enjoys nibbling on grass, some experts suggest buying a tray of grass just for Fido to eat, which will help prevent him from ingesting any chemicals like pesticides. You can also introduce raw herbs or cooked vegetables into his diet (most dogs prefer their veggies cooked rather than raw). If, however, you notice your dog suddenly eating large amounts of grass — especially if it’s accompanied by repeated vomiting — it’s time to find a vet and call right away to make sure it’s not a symptom of an underlying health problem. 2) Why does my cat like sleeping on my head? If you commonly wake to find your cat doing her best nightcap impression, you’re not alone. Many cats seem to think the best spot for sleeping is on top of their owners’ heads. But why? According to an article on PetMD that quotes Marilyn Krieger, certified cat behavior consultant and proprietor of the Redwood City, California-based operation, The Cat Coach, cats like to sleep on their owners’ heads for a few reasons. First, it helps them stay warm while they sleep. Since much of our body heat escapes through our heads, cats can use our noggins like an electric blanket. For those of us who tend to toss and turn a lot while we sleep, our pillows are also a much more restful location than elsewhere on our beds. Finally, your cat may enjoy your scent and feel safe and comfortable sleeping on your head — making this behavior just one more weird, wonderful way that cats say, “I love you!” So while your cat may not be the most comfortable headgear — especially while you’re trying to sleep — you can file this one under “weird to us — normal to cats.” 3) Why do dogs sniff each other’s rear ends? When we meet someone new, we generally smile, say hello and perhaps shake hands. Dogs, on the other hand, bury their noses in each other’s you-know-where. To us, it’s the ultimate faux pas, but to them, it’s as polite as can be. But why? According to Dr. Lynn Buzhardt, the answer is quite simple — dogs have an unbelievably powerful sense of smell, and taking a good, long whiff of a stranger’s rear end tells them everything they need to know. “An average dog has a sense of smell that is about 100,000 times more sensitive than his owner’s, partly because dog noses contain 150 million olfactory receptors while human noses only have 5 million,” Buzhardt explains. “And dogs devote about 1/3 of their brain mass to the detection and identification of odors, while humans utilize a mere 5% for olfactory purposes.” The “butt factor” comes into play due to two small glands on either side of a dog’s anus. These glands are very similar to a skunk’s, but since the glands are usually emptied when dogs defecate, most owners aren’t even aware of them. Dogs certainly are, however, and it’s these secretions that they’re smelling when the butt sniffing occurs. “Dogs sniff butts as a form of greeting and obtain vital information from the anal secretions,” Buzhard says. “Is this dog friend or foe? Is he going to be a good date? Will he be aggressive? Is he feeling ill? And because the odor is unique to every dog, two dogs can quickly determine if they’ve met before. That aroma emanating from the anal region is a unique form of canine identification.” So there you go — disgusting to us, but perfectly normal for dogs. 4) Why do cats knead? Cat lovers have all experienced the cute and — when claws are involved — often painful phenomenon of being “kneaded” by their cats. But why do our cats sometimes treat our laps like raw dough? The behavior starts during kittenhood when they knead their mothers’ bellies to help stimulate milk production. And since that experience provided them with lots of positive memories, cats continue it into adulthood to express their love and contentment. The happier and more comfortable they are, the harder they dig in, with (ouch!) or without their claws. Cats also have scent glands in their paws, so in addition to showing affection, it’s quite possible that your cat is also laying claim to you in the process. If your cat uses her claws while kneading, putting a blanket on your lap and keeping her claws trimmed can help keep this perfectly normal cat behavior pleasant for both of you. 5) Why do dogs circle before lying down? Does your dog take a few tight laps around his bed before lying down? If so, he’s not alone — it’s another behavior that seems strange to us but is perfectly normal for canines. But why do they do it? Most experts believe that circling is another behavior that’s leftover from our pets’ wild dog days when they had to create “nests” in the wild for sleeping. When you don’t have opposable thumbs, walking around in circles is the best way to smooth out a lumpy surface before a comfortable snooze. To test the theory, noted psychologist and author Stanley Coren conducted an experiment that involved placing dogs in pens away from their owners to see what would transpire. He tested 62 dogs total in two carpeted pens — half in one with fabric that was short and smooth, the other half in one with material that was loose and shaggy. While 5 dogs (19%) circled the smooth surface before lying down, more than half (55%) circled the shag before settling in, with some digging and poking at the material as well. While Coren admits that the results of his experiment don’t rule out other possible reasons for this behavior, it appears that the nesting theory is pretty solid — and that circling can look strange to us, it’s perfectly normal for dogs. 6) Why do cats hate water? It’s a well-known fact that unlike their canine counterparts, the average cat is not a huge fan of water. But why? One explanation is that most domesticated cats evolved from regions or the world known for being hot and dry — such as the Middle East (think all that cat imagery in ancient Egypt) — so a love of water isn’t really in their DNA. Being soaking wet can also weigh down their coats, making them less quick and maneuverable and creating a sensation that makes cats anxious. Finally, it could have something to do with their relatively high average body temperature mentioned earlier, which is hard to maintain when soaking wet. So if your cat is hydrophobic, she’s in good company. It’s just another cat behavior that may seem odd to us but is perfectly normal for them!