Nice Mice

Researchers are probing the genetic roots of human empathy with some regular Stuart Littles.

Certain mice saw a bud get shocked at the sound of a tone, then later froze in fear when they heard the same sound: They made a connection between another mouse's experience and their own.

When another group of mice heard the tone, zippo.

The former were genetically engineered to be social and seek out others. The latter were from a strain of reclusive rodents.