Biology
Olfactory Imprinting and Natal Homing in Anadromous Salmonids
Quick fact
Salmon memorize the unique 'smell' of their home stream as juveniles, and later use this olfactory memory to guide their final approach to their natal spawning grounds—a feat that can lead them to the precise gravel bed where they hatched.
Why this is interesting
Imagine a fish that can find its way back to the exact stream where it was born, years later, after swimming thousands of kilometers in the open ocean. How does it do it?