The Chemistry of Instinct: Here's What Makes Mice Freeze in Fear

It's the essence of instinct: If you take a lab mouse who has never caught a glimpse of a cat and waft a little eau de feline towards it, the mouse will freeze in fear, and will then back away from the source of the odor. Now researchers have pinned down the chemical signals the mice are reacting to--and have shown in the process a fascinating new form of inter-species communication.