How does a dead fruit fly with caved in eyes that is full of parasites,beat real life photos ?And why are macro photos dueled against tigers in a zoo and naked woman ? Play with some jumping spiders, sneak up on an Dragonfly that is talent. Any one can kill something and make still photos!
The reason that Lions duel Insects is because all of the images in the Animals category go up against one another in the duels, images duel at the category level, so every subcategory with in a category duel one another.
That said, there should be no images of nude women in the Animals category. There is a category, Novices Only, where all subjects duel all other subjects in the category, it is a mixed subject matter category that can include people, objects, animals etc.
I have not seen the fruit fly image that you are talking about, but art is in the eye of the beholder / photographer.