The branch of medicine dealing with diseases caused or borne by arthropods. As vectors of bubonic plague (via fleas carried by rats), typhus (via lice), malaria, dengue fever, and encephalitis (via mosquitoes), lyme disease (via ticks), and more, arthropods are of great interest to epidemiologists. Bugs with "bugs", double-iw. Arthropods constitute a whopping 90% of Earth's biomass; the phylum is amazingly diverse and their impact on human health is diverse as well. Spiders, scorpions, and many insects inject venom by bite or sting; this aspect of medical entomology is covered by toxicology. Some defensively secrete acid, causing blisters and burns. Mosquitoes, ticks, and lice are double trouble because they are themselves parasitic, and also carry disease as noted above. Flies can cause myiasis - Latin sweet-talk for infestation of living tissue with fly larvae (maggots). As food, crustaceans (shrimp, lobster, crabs) can provoke allergic reaction and/or carry environmental contaminants (e.g. mercury and dioxin).