The Origin of Animal Idioms

Everybody has a friend who can't keep a secret. That person is always "letting the cat out of the bag." But where did the bag come from, and why is there a cat? In the Middle Ages, vendors in public markets sold pigs and chickens in sacks. Some dishonest vendors put cats in the bags instead. When the buyer got home and opened the sack, the cat came out and revealed the vendor's secret.

If you want the real scoop, you need to get it straight from the horse's mouth. This confusing phrase has been used since the early 1900s and comes from the world of horse racing. Raceday betting tips from horse jockeys and trainers were preferred by racetrack enthusiasts. Some track gamblers started saying info straight from the horse's mouth would be even better, and this phrase meaning "the best, most accurate information" was born.

No doubt you've been in a situation where someone was taking too long to get somewhere or do a task. You might say they were "moving at a snail's pace." This idiom is fairly self-explanatory—it simply means that something is taking a long, long time. It's been used since at least the 16th century when William Shakespeare included it in his play Richard III.

Imagine chasing a flock of wild geese and trying to catch one. You won't succeed, but you'll get exhausted and frustrated in the process. We use this phrase both when we think someone is wasting our time and when we search for something in many places but don't find it. An English poet named Gervase Markham coined the original version of the phrase in a late 16th-century book about horsemanship.

We're all animal lovers here, and we can tell you that dogs do not eat other dogs under normal circumstances. In fact, this saying comes from a 16th-century Latin proverb, "a dog does not eat the flesh of a dog." When someone says that it's a dog-eat-dog world, they mean that the competition is so vicious that even well-tempered dogs would resort to hurting one another to get ahead.

If an elephant came into your living room, you'd definitely see it. Right? Poet Ivan Krylov wasn't sure. He wrote a fable called "The Inquisitive Man" about a person who goes to a museum and takes in all the small details but doesn't see a massive elephant standing in the middle of the room. Today, we often use the phrase when we know there's something important to discuss, but we ignore it.

No one is sure exactly when this idiom meaning "slow down" or "hold on" was coined. Some believe it comes from a time when horses, carriages, and stagecoaches were the primary methods of transportation. Instead of saying, "hold the bus," people might have appealed for carriage drivers to hold their horses so they could hop aboard.

If you're stuck in the dog days of summer, you're living through long, extremely hot days. This odd phrase doesn't come from earthly dogs though. It can be traced to early Rome and beliefs about the constellation Canis Major. The brightest star in the group, Sirius, appeared from late July into August. It was the hottest time of the year in Italy, and ancient Romans believed that all that heat came from the dog constellation.

If you go to a restaurant and have a lot of food left over, you probably expect the waitstaff to offer you a "doggie bag," or to-go container. Food shortages were common during World War II, and dog food could be hard to come by. Cafes in San Francisco started offering "Pet Pakits" so people could take leftovers and scraps home to feed animals. The phrase "doggie bag" later became the generic name for this practice. We still use it today—even though we aren't feeding our dogs the leftovers anymore.

When someone is ungrateful for a gift because they don't think it's valuable, you might tell them not to look a gift horse in the mouth. Why not? A horse's value is generally tied to its age, and a horse's age can often be determined by looking at its teeth. Hence you should be grateful for things that are given to you instead of trying to find out how much they're worth. The phrase is attributed to St. Jerome, who used it in a proverb in 400 C.E.