Tropical army ants display an incredible behavior. As a column of ants marches through the rainforest they encounter small ditches or other barriers across which they form a bridge with their bodies so that other ants can cross over: This is amazing. How do insects know to do this? The behavior is obviously inherited but how is it passed on? Genes code for proteins and proteins build structure. What is it that codes for behavior? If it's proteins then how do protein molecules in the teensy brain of an ant translate into behavior?
And how does instinctive behavior evolve in the first place? According to the standard darwinian story, natural selection works on mutated genes to create novel structures, but if behavior isn't a function of an organism's genome how does it ever arise?
I wish that those who are so certain that all explanations are naturalistic, materialistic explanations would offer a plausible answer to these questions because they comprise what I think is perhaps the greatest mystery about living things - the origin and transmission of instinctive behavior.