Take any species-specific behavior we find in the animal kingdom, particularly among the lower phyla and classes of organisms. Whether it's courtship, nest-building, webs, threat displays, migratory behavior or whatever, the behavior must be passed on from generation to generation, it's not learned, and it must somehow be an expression of information. So what's the carrier of that information and how did the behavior/information ever evolve in the first place?
Here's one of the photos of a structure built by the caterpillar of a moth called a bagworm:
As the photographer asks: How did the caterpillar manage to create such symmetry? How did it get twigs of just the right size to create the log cabin? I'd add to these questions, how did it know to do all this and to build it just this way? How do birds know how to build their nests? How do spiders know exactly what kind of web to spin?
Animal behavior is mysterious enough, but it seems literally incredible on the materialist view that it's solely the product of random mutations and chance genetic drift. It's also hard to see how this structure could have had a selective advantage over any of the thousands of simpler structures the bagworm could have adopted.
Perhaps biologists already have all this worked out, but I've never seen an explication of it, and if anyone knows what it is please let me know.