Insect Navigation: Brains as Symbol- Processing Organs

Digger wasps dig nest burrows in which they lay an egg. They cover the burrow entrance with pebbles, making it all but invisible, then fly off in search of insect prey. They sting their prey to paralyze it, carry it back to the burrow, open the burrow, drag the prey inside, exit the burrow and close it up again. The larva that hatches from the egg eats the paralyzed, still living prey. This aspect of the natural history of digger wasps cautions us against an overly sentimental view of the workings of mother nature, at least at the insect level. Quite aside from pointing up this moral, it raises two questions of profound interest to contemporary cognitive scientists and neurobiologists: (1) How does the wasp find her way back to her invisible nest? (2) What does the answer to that question tell us about the nature of the brain?