Someone got to this here blog after typing a question into Ask.com. Theirs is a cute, thought-provoking question and, since I respond to my readers with compassion and honesty, it is my privilege to answer it straight out: Q: How big are houseflies? A: My fingernail is the size of a cow. You see, houseflies are both small, and big. They seem small, the size of a fingernail, but when you slowly sneak your eye in real close to observe one cleaning her face with her teensy hands, they look big. Cow size, with a cute fuzzy behind. So, the long answer is that houseflies are the size of the nail on my index finger and also of a cow. Using a variant of Pythagoras’s Theorem, a 2 + b 2 = c 2 , we arrive at the final answer. You could see a different viewpoint at Wisegeek.com , but why? See also: Why I Hate Flies | Fly image from GNU