EXPERIMENT    A female digger wasp
   excavates  and  cares  for  four  or  five separate underground nests,
   flying  to  each  nest  with food for the single larva in the nest. To
   test  his hypothesis that the wasp uses visual landmarks to locate the
   nests,  Niko Tinbergen marked one nest with a ring of pinecones. After
   the  mother  visited  the  nest  and  flew  away,  Tinbergen moved the
   pinecones a few feet to one side of the nest.
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RESULTS    When  the  wasp  returned,  she  flew to the center of the
   pinecone   circle  instead  of  to  the  nearby  nest.  Repeating  the
   experiment with many wasps, Tinbergen obtained the same results.
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CONCLUSION    The  experiment  supported  the  hypothesis that digger
   wasps use landmarks to keep track of their nests.
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   Tinbergen  received  the  1973  Nobel  prize in Medicine with Karl Von
   Frisch and Konrad Lorenz.
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