Horse Flies are larger than House Flies (up to 1 in long) and dark-colored with clear wings. They have very large eyes that extend sideways. The females have a nasty bite.
Horse Flies are most abundant during the summer and only fly during the day. They breed in moist areas.
Could it be? Deer Flies, a species of Horse Fly, are smaller (.4 in long) and narrower with dark patches on their clear wings.
Did you know? Horse Flies can be traced back to the Late Jurassic period in China, 145-160 million years ago.
See Also: Black Fly, House Fly, Hoverfly
                    
                        Easy - numerous and usually easy to spot
                        in the habitats listed at the appropriate time of
                        year.
                
            
                    
                        Forests are large areas of trees growing close
                        together.
                
            
                    Grasslands are large open areas covered with
                        grasses. They have very few trees or shrubs. 
                        This habitat includes prairies and tundra.
                
            
                    
                        Wetlands are low-lying areas that are covered by
                        water all or most of the time and support a variety of 
                        aquatic plants. This habitat includes rivers, streams, 
                        lakes, ponds, bogs, and marshes.