Travel through the grasslands of central and western America and you'll likely see and hear countless prairie dogs.

Millions of the adorable burrowing rodents call these plains home, and while they may be a common sight, they have many unique characteristics.

Read on for some fascinating facts about prairie dogs.

1. They were once the most abundant mammals in North America.

prairie dogs sitting on a mound of dirt

Photo: Larry Smith/flickr

There are five species of prairie dog — black-tailed, white-tailed, Gunnison's, Utah and Mexican — and black-tailed prairie dogs once numbered in the hundreds of millions.

However, hunting, poisoning and habitat loss decreased the population by more than 95 percent, and today the species numbers somewhere between 10 million to 20 million.

2. They have well-organized homes.

prairie dog in burrow

Photo: Kabacchi/flickr

Prairie dogs live in complex underground burrows with designated areas for nurseries, sleeping and toilets. The tunnel system is designed to allow air to flow through them, providing ventilation, and every exit also has a listening post.

3. They live in towns.

prairie dogs in snow

Photo: USFWS Mountain-Prairie/flickr

Prairie dogs are social animals, and they live in family groups called coteries that typically contain an adult male, one or more adult females and their young. Coteries are grouped together into wards, and several wards of prairie dogs make up a town or colony.

The largest town ever recorded belonged to a large group of black-tailed prairie dogs in Texas and was about 100 miles long.

4. They 'kiss.'

prairie dogs kissing

Photo: U.S. Fish and Wildlife Service/flickr

Prairie dogs often "kiss" when they come and go in the area around their burrow. When they do so, they'll touch noses and lock their teeth with one another, which allows them to determine if they're members of the same family group.

5. They're ecologically important.

prairie dog holding a blade of grass

Photo: Stuart Richards/flickr

As a keystone species for the prairies, entire ecosystems rely on these tiny mammals. Their tunneling aerates the soil, and their dung is high in nitrogen, which improves soil quality.

Prairie dogs are also a food source for many animals, and their deserted burrows provide nesting areas for a variety of species, including snakes and burrowing owls.

6. They have their own language.

two prairie dogs communicating

Photo: Larry Smith/flickr

Prairie dogs have a complex means of communication that's even better than that of chimpanzees and dolphins.

After recording and analyzing prairie dog calls for more than 30 years, Con Slobodchikoff of Northern Arizona University found that the animals have barks and chirps that communicate numerous messages.

Many of these messages are designed to alert others in a colony about the presence of a predator, and the animals' communication is so advanced that not only do they have different calls depending on the type of predator, but they also make sentences that describe the predator.

Prairie dogs can embed information about the predator's size, color, direction and speed in a single bark, and a colony — which can include hundreds of animals — consistently uses the same barks to describe the same predators. Prairie dogs even have a specific call that describes a human with a gun.

By showing captive prairie dogs a series of shapes, Slobodchikoff has also found that the animals can develop new calls to share information about items they've never seen before.

7. They do 'the wave.'

black-tailed prairie dog jump-yip

Photo: USFWS Mountain-Prairie/flickr

Prairie dogs are under constant threat from predators like hawks and coyotes, so they protect themselves by staying in continuous communication. This often results in contagious behavior where one prairie dog's action is mimicked by others.

One of these often-mimicked displays is the jump-yip, in which one animal stands on its hind legs, stretches its arms out, throws back its head and yips. Upon hearing the sound, other prairie dogs copy the behavior, and jump-yips spread throughout the colony.

Why do they do this? Researchers have been studying the behavior for decades, trying to discern why the animals jump-yip in a variety of situations: when predators arrive, when predators leave, when keeping watch or when defending territory.

Recently, scientist at the University of Manitoba suggested that the wave-like response is an indicator that everyone in the group is being vigilant. By initiating a jump-yip, one prairie dog is reminding the others to pay attention, which explains why prairie dogs jump-yip in many different situations.

Watch some jump-yipping prairie dogs in the video below.

Related on MNN:

7 things you didn't know about prairie dogs
They build their own towns, they help the environment, and they even talk about us.