SOURCE: Kirsten Jensen, University of Kansas; Erik S. Loker, University of New Mexico; Steven A. Bullard, Auburn University; Centers for Disease Control and Prevention; WHO World Malaria Report 2015; Mayo Clinic. Note: Colors and sizes are diagrammatic..

You won’t be able to see any of the 20 million or so creatures in the National Parasite Collection for a while because displays take a few years to create. In the meantime, here are some of the collection’s most fascinating creepy-crawlies, chosen by Anna J. Phillips, research zoologist at the Smithsonian National Museum of Natural History.