The two species of mice were successively bred, and those hybrids built long, two-tunnel burrows like oilfield mice - showing that the behaviour is a "dominant" trait.

BBC: Mouse burrowing 'in their genes'

Its rise and fall resembles the story of other cities, but on the ground, there's nothing like it -- exactly the trait that makes any place worth a visit.

CNN: STORY HIGHLIGHTS

Until recently, little had been known about this species, apart from the fact that like many deep sea creatures it has the ability to glow - a trait called bioluminescence.

BBC: Glowing shark scares off predators with 'lightsabers'