one of the classes i took last semester was a project study (is that how it is translated?) about food webs.
we tried to find out for ourselves who is eaten by whom.
spent a day in the field (a wheat field, to be exact), got to try different methods for catching arthropods, and eventually had isotope analysis done, to try and shed some light on the actual predation relationships.
REALLY interesting stuff, and a fun day out in the air. :-)