Naked mole rats

Naked mole rats invade neighbouring colonies and kidnap their babies

Naked mole rats (Heterocephalus glaber) are normally very friendly

Minden Pictures/Alamy

Naked mole rats go to war. The sociable little mammals have been observed invading neighbouring populations and even kidnapping newborn pups, who become workers in the conquering colony.

The rats (Heterocephalus glaber) are one of a handful of mammal species that are eusocial: they live in large underground colonies in which most members are sterile workers and only one individual, the queen, reproduces. They have been compared with eusocial insects like honeybees.

Stan Braude at Washington University in St Louis, Missouri, and his colleagues made crucial observations of the …