I did my BSc thesis at nematology. I looked at whether it is possible to pinpoint food preferences of nematodes.
In this case, food preference is deduced from physical association, and therefore I looked at soil communities, and not the contents of the nematodes digestive tract. My findings pointed in the right direction, but because the sample size was too small, no significant results were found. However, since this was a pilot experiment, my results are useful for further research on the subject. I enjoyed my stay at nematology very much. The people are very nice and I could ask anyone for help anytime.