Naked mole rats have accents -- and use them to discriminate against foreigners

Naked mole rats are very communicative, chirping, squeaking, twittering and grunting to one another.

(CNN)Strangers are just friends you haven't met -- unless you're a naked mole rat.

Arguably nature's least beautiful animals, naked mole rats speak in dialects local to their own colonies and are hostile to outsiders, according to a study published Friday.
Naked mole rats are "really highly unusual in that they're the most social rodent that we know of," Gary Lewin, senior author and professor in neurobiology at Germany's Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), told CNN.
    The furless rodents can live in colonies of up to 300 members, and though there is only one breeding female per colony, "every animal in the colony has a role: Some are soldiers, some are workers, and they cooperate," he said. "It's always been a mystery how they can be so organized."
    Some mole rats even band together to assassinate their queen.
    Found in arid parts of East Africa, naked mole rats weigh around 2.8 ounces and have a body measuring up to 3.5 inches and a tail that can reach 2 inches.
    Though something of an acquired taste aesthetically, these wrinkled, pinkish, bald rats are renowned for their extremely low cancer rates, their slow rate of aging, and resistance to pain.
    They are very communicative and can often be heard chirping, squeaking, twittering and grunting to one another. But scientists wanted to understand the role of these vocalizations in their social life.
    Over two years, researchers from the MDC and the University of Pretoria in South Africa recorded 36,190 "chirps" -- noises very similar to a bird tweeting -- made by 166 rats belonging to seven different colonies.
    Using an algorithm, the team analyzed the acoustic properties of the individual vocalizations, and discovered that each colony had its own "accent" or dialect.
    The development of a dialect points to one of the rodent's less-savory characteristics: xenophobia.