On Isla Nublar, the staff of the park quickly learned how much waste the large dinosaurs, especially the Sauropods made daily. As Henry Wu explained, the droppings left behind by the large animals did not decompose quickly, and they were rather large. This posed obvious sanitary and logistical problems in managing the park. The solution was to breed Procompsognathus in significant numbers since they had evolved to eat the droppings of other animals. In addition, the droppings of the Procomposgonathus itself was able to be broken down by contemporary bacteria, solving their problem.
Jurassic Park By Michael Crichton, page 122(First Edition, Thirty-fourth printing)