Anyone who has visited a beach on Cape Cod in July has probably experienced the painful bite of a greenhead fly.  Why do these flies bite and what is the Cape Cod Greenhead Fly Control District doing to reduce the annoyance level? How do those blue boxes on the marshes work and what can you do to fight the bite?  Learn the answers to these questions and more. This is an in-person program at the Library on Monday, July 20 @ 3:00 pm. Registration for this event is strongly recommended!