Seed & Hull Digester 33.9 oz - Protects birds from unwanted parasites and e-coli bacteria. Grounds beneath feeders are highly contaminated from bird droppings, parasites and e-coli bacteria from moldy birdseed. A simple spray will remove these harmful contaminants.Birdseed, hulls and other organic materials are decomposed, digesting them down into basic components that are easily absorbed into the environment.