United States Fish and Wildlife Service list of threatened and endangered arthropods species may be treated as endangered or threatened if it resembles in appearance a species which has been listed and enforcement personnel would have difficulty distinguishing between the listed and the unlisted species; if the effect of this difficulty is an additional threat to the listed species; and if such treatment of the unlisted species would improve protection for the listed species. United States Fish and Wildlife Service list of threatened and endangered arthropods List of threatened and endangered arthropods, including insects, arachnids, and crustaceans under the United States Endangered Species Act as of October 2013. Key to Listing Status
Arthropods in film higher percentage of oxygen, arthropods would be able to grow quite a bit larger before their trachea became too large and could not grow any more. In fact, in the early years of the earth, when the atmosphere was more oxygen-rich, dragonflies the size of crows were not an uncommon sight. Winsor McCay, one of the founders of animation, made the first animated film about insects in 1912, titled "How a Mosquito Operates". In the early 20th century, it was technically easier to include insects in animated films, which are drawn, over live-action films which would require more advanced techniques