You Are Here by Colin Ellard

animal can path integrate as well as the desert ant. Given the lifestyle of these hardy critters, this is not too surprising. These ants live in barren conditions with sparse local cues to help them navigate, and climatic conditions where mistakes could bequickly fatal. To see how our own abilities to path integrate compare with those of other animals, it would be more sensible for us to look somewhat closer to home in the great tree of life. Fortunately, there is no shortage of research on path integration in mammals like us.
    One of the first path-integration experiments with mammals was conducted by a husband-and-wife team of psychologists, Horst and Marie-Luise Mittelstaedt. The Mittelstaedts used female Mongolian gerbils for their experiments, and they took advantage of the well-honed maternal instincts of nursing mother gerbils. When young pups stray from the nest, their mothers are diligent about seeking out their errant children. They pick them up gently by the scruff of the neck and return them to their nest. Even in complete darkness, mothers can retrieve their pups by localizing the tiny, high-pitched squeaks the pups produce when separated from them. The Mittelstaedts designed a circular arena with a small container on the outside edge that could hold a nursing mother and her pups. While in complete darkness, one of the pups was removed from the container and placed in the middle of the arena. The mother would instinctively begin hunting for the lost pup. Like a desert ant, the gerbil mother would search in a somewhat meandering path, but once the pup was found the mother made a beeline for the nest, just like the ants collecting food in the desert.
    To test whether the gerbils were using path integration, the Mittelstaedts added a small platform to the center of the arena, which could be rotated at different speeds. Again, a pup was removed from the nest and placed on this platform. When the mother stood on the platform with the retrieved pup in her mouth, the experimenters rotated the platform. If they rotated the platform very slowly so that the mother could not sense the movement, she set off for the nest in the wrong direction. The mother’s homeward course could be predicted simply by the magnitude of the platform rotation. Thisproves that, like Wehner’s ants, the Mittelstaedts’ gerbils were using path integration to track their spatial location relative to the nest. 7
    Similar experiments with other animals have suggested that the ability to path integrate is common in nature. 8 Hamsters led across a large space in the darkness, following a choice morsel of food like the legendary dangled carrot, will turn and run to a hiding place once they have received their treat. Dogs shown a biscuit and then led away on a winding course while wearing a blindfold and headphones can, when released, turn and run to the location of the food with considerable accuracy. Though the path-integration abilities of dogs, gerbils, and hamsters are impressive, there have been no tests of the ability of an animal to path integrate over the same spatial scales as routinely tested in ants. In a way, this would not be a fair comparison. Because of their sensitivity to light polarization, ants have a built-in compass that can always be used to assess direction. Most other animals don’t have such an accurate compass and must rely entirely on a record of their own movements obtained from their vestibular system. To understand why this is a disadvantage, we will need to turn our eyes upward.
IT IS ROCKET SCIENCE!
    In another desert, far from the home turf of the African desert ant, Robert Goddard toiled in the heat of Roswell, New Mexico, following a boyhood dream to send rockets far into space, a prelude to a mission to Mars. Goddard’s quest began at the dawn of the twentieth century when, as a seventeen-year-old boy, he sat in the bough of a cherry tree, looking down at the ground and imagining the view from Mars. He dreamed of