Most of us don’t care much for rodents. Some are just plain nuisances, while others are destructive. But they’re not all terrible. Here are the facts, both good and bad!
• The word “rodent” has its roots in Latin word “rodere,” which means “to gnaw, eat away, or prey upon.” Rodents belong to the order Rodentia, with more than 2,200 different species, and are all mammals covered with hair, accounting for about 43% of all mammals worldwide. They all have tails, and give birth to and nurse living young. Rodents also have the structure of their teeth and jaws in common, with powerful and prominent upper and lower pairs of teeth. Their incisors grow continuously, about 1/8 inch per week.
• Most rodents are herbivorous, consuming seeds, stems, leaves, flowers, and roots. A few are omnivorous, feeding on both plants and animals. When it comes to food, rodents are hoarders, taking more than they can eat, saving it to hide for later. This practice is aided by cheek pouches found in some rodents, bags that can stretch from the mouth to the front of the shoulders, enabling them to store food.
• Mice and rats are the first rodents that come to mind, but the order also includes beavers, squirrels, chinchillas, gerbils, gophers, woodchucks, porcupines, and prairie dogs. You might think moles and hedgehogs would be on the list, but they are a different mammal species.
• Rodents vary widely in size. The largest is the capybara, a South American animal with an average weight of about 110 lbs. (50 kg.) The smallest, the pygmy jerboa, found in Pakistan, might be small, 1.7 inch long and weighing less than 1/5 ounce, but it’s capable of jumping up to 9 feet! In North America, the beaver is the largest rodent, with a body length of about 47.2 inches (120 cm), weighing up to 66 lbs. (30 kg). This rodent’s tiny eyes have a membrane for protection while swimming underwater.
• The lifespan of rodents also differs greatly. Rats live about 12 months, but larger rodents live longer, such as beavers and porcupines, which can live over 20 years. The naked mole-rat has been documented at 30 years.
• Sometimes you might feel your heart racing, but it’s nothing compared to the heart rate of an adult mouse, about 630 beats per minute. The human heart beats between 60 and 100 bpm. Some rodents’ extremely high metabolism necessitates 20 meals a day.
• Nocturnal rodents, active at night, navigate the dark with their long sensitive whiskers. They brush or tap these whiskers, or vibrissae as they are called, on objects to ascertain the size and shape, a practice called “whisking.” They also have oversize eyes, some of which are sensitive to ultraviolet light.
• Beaver trapping and fur trading was a widespread business in the history of North America, resulting in the near extinction of several species in the mid-19th century. In South America, chinchillas are raised strictly for their fur, the most valuable in the world. Wild chinchillas are even more expensive, with coats made with 400 pelts selling for as much as $100,000.
• If it seems that rat populations run high in some areas, it’s because the brown rat gives birth to 22 offspring at a time. The typical house mouse can produce as many as 14 litters a year! The Centers for Disease Control estimates that mice and rats spread upwards of 35 diseases through human contact, whether it be directly through their feces, saliva, or bites, or indirectly through various parasites.