How do some birds, turtles, and insects possess navigational abilities that rival the best manmade navigational technologies? Who or what taught the honey bee its dance, or its hive mates how to read the complex message of the dance? How do blind mound-building termites master passive heating and cooling strategies that dazzle skilled human architects? In The Origin of Species Charles Darwin conceded that such instincts are "so wonderful" that the mystery of their origin would strike many "as a difficulty sufficient to overthrow my whole theory." In Animal Algorithms, Eric Cassell surveys recent evidence and concludes that the difficulty remains, and indeed, is a far more potent challenge to evolutionary theory than Darwin imagined.