Naked mole rat
Naked mole rats feed primarily on very large tubers (weighing as much as 1000 times the body weight of a typical mole rat) that they find deep underground through their mining operations, but also eat their own feces (coprophagia).  A single tuber can provide a colony with a long-term source of food—lasting for months, or even years, as they eat the inside but leave the outside, allowing the tuber to regenerate. Symbiotic bacteria in their intestines help them digest the fibres.