Flies don't care about what they eat. I think it's because they know they won't live long no matter what they do. Not only that, they have even more things to worry about than we do; It's their job to travel back and forth from the garbage can in the backyard, to the dog poop in the front yard, and then inside to the clothes hamper, running into every window before finding their way back out to the dead squirrel in the alley. All that time dodging fly swatters, bug sprays, hungry birds, and worst of all, the dreaded spider web. A fly's life is not easy at all, but then again, they have no worries about eating anything they want whenever they want. That part I envy.