Parasites are organisms that live on or in a host. They subsist on the host's nutrients at the host's expense. Parasites can be found around the world. Infection symptoms vary depending on the type of parasite. Examples of parasites and their infections include lice leaving their larvae behind in hair, giardia causing severe diarrhea and stomach cramps, tapeworms causing the host to be fatigued due to a lack of nutrition and a poor appetite, and an infected mosquito's bite resulting in malaria, bringing about high fever, chills, and weakness. Find out more information about a variety of parasites, how to avoid them, and how to treat infections.