- Turns out the seven-human-years-per-dog-year formula for determining a dog's age isn't actually the best available. The first year of a puppy's life is equal to about 21 human years; every succeeding year is equal to about four human years.

- Before puppy love (the kind that human teenagers experience) was called puppy love (the first recorded use was in 1834), it was known as "calf love." Equally immature, but somehow less adorable.

In fact, the language of love is always changing. Why, it wasn't too long ago that "flirting" with a "hunk" meant something entirely different than it does today. The word hunk used to refer to a slow-witted or fat man, and the verb to flirt originally meant "to snub."

- Just like many human babies, puppies are often born with blue eyes that darken in the first few months of their lives.

- As for when it's safe to neuter or spay your puppy, puppies are generally spayed or neutered between the ages of five and eight months. But recent studies have shown that the operations are safe in dogs as young as six weeks. And just so you know, some puppies begin humping legs at the tender age of four weeks. They aren't sexually mature for several months, but it's never too early to start practicing!

The Scoop on Poop

It's an ancient question: Why do puppies, um, eat their poop? There's a name for that phenomenon, incidentally - coprophagia, which we'll use because it sounds less disgusting than the alternatives. Some veterinary scientists believe that puppies engage in coprophagia due to mineral deficiencies, and that giving dogs a multivitamin will address the issue. Others argue that it's a result of owners using the old "rub their nose in it" potty-training strategy.

Adapted from Scatterbrained (HarperCollins), which is available at leading bookstores. For a daily dose of quirky fun, visit mentalfloss.com and check out mental_floss magazine at your local newsstand.