Transcript:

Today on Animal Fact Files we’re discussing mice. There isn't a proper taxonomic group that includes all mice. Some animals with the common name "mouse" are marsupials while the vast majority are completely unrelated placental mammals. To take it a step further, the terms "mouse" and "rat" are also not taxonomically separated. Typically, smaller species are known as mice while the larger individuals are known as rats, but there are even some animals commonly known as gerbils classified in the "true mouse" family, so it's not all super clear when using common names. Put simply, we're talking about the Muridae family.

To be fair, part of the confusion with this can be attributed to the fact that this is one of the largest families of mammals alive today. There are more than 1,300 rodent species in this family alone! In fact, they make up nearly two thirds of all rodent species on Earth! There's plenty that remains unresolved in terms of their relationships with one another, so some discretion is necessary when describing them as a general whole.

Mice are found all over the world; they're a cosmopolitan group of mammals. The only area they don't currently inhabit is Antarctica, although they have colonized some of the warmer, outer islands of the continent, so they're working their way there. These small rodents are generalists in their habitat selection, as well. They can survive in swamps, meadows, mountains, tundras, deserts, and even human-made environments. Some spend their time in trees while others are ground dwellers that dig below the dirt and live in underground burrows. Some species are even semi-aquatic!

These animals can typically be told apart from other small furry animals by their long, naked tail, round eyes and ears, pointed nose, and whiskers. Mice are generally a few inches long and their tails measure about the same. On average, they're between one and two ounces (30-60 g) in weight. Of course, it's important to remember there is huge variation in this family, so these numbers are vague at best. They also range in when they're active. Some mice move around at night while others actually prefer the day!

As their habitat and appearance range vastly, so too does their diet. Mice eat plants, animals, fungi, and more. There is a fully carnivorous animal with the common name "mouse" - the grasshopper mouse - however, it's not classified in the same family being discussed in this episode. See how confusing things can get without scientific names? As rodents, mice have two sets of continuously growing incisors, one set per jaw, no canines, and anywhere from one to three molars depending on their dietary needs.

Small mammals often have short lifespans and mice are no exception. On average, these mammals live about one to two years in the wild. They reach reproductive age within just two months of their birth and mother's can produce upwards of a dozen babies! Mouse gestation takes around three weeks, which means in a single year there can be multiple generations.

These rodents have a reputation as vermin, so we're not going to focus on that here. Instead, we want to highlight how valuable mice are in our world! Due to their diet, mice do some serious work at keeping our forests, grasslands, and even backyards healthy. They help spread seeds and fungal spores as well as ingest massive amounts of "pest" insects and their larvae. That's not even mentioning the benefit laboratory mice have helped with medical advancements for humans and other animals the world over. Plus, mice feed all kinds of other predators and contribute substantially to the natural food web.

For more facts on mice, check out the links below. Give a thumbs up if you learned something new today. Thank you to our Patrons SpikeSpiegel93, Dad, and everyone else for their support of this channel! And thank you for watching Animal Fact Files!