There are several phenomena that any naturalistic version of evolution has an exceptionally difficult time explaining. Among these are the origin of life, the origin of human consciousness, insect metamorphosis, sexual reproduction, and animal migration.
The latter problem is the topic of a two-part series of short videos put out by Illustra Media on animal migration. The salmon life cycle is fascinating, but that it's able to return to the exact stream in which it spawned after having been off in the middle of the Pacific ocean for three years is just astounding.
How does it do it? The answer is by detecting and following the gradient of minute amounts of chemicals characteristic of that particular stream. This beautiful video explains how it does this.
As you watch the video ask yourself how this or any of the processes mentioned in the first paragraph, could have ever evolved by blind, unguided, purposeless mechanisms like Darwinian evolution. No Darwinian scientist has an answer to that question. They just believe in an act of blind faith that they did:
Illustra Media will release Pt.II next week.