allergy The inappropriate reaction by the body’s immune system to a normally harmless substance. Untreated, a particularly severe reaction can lead to death.
anxiety A nervous disorder causing excessive uneasiness and apprehension. People with anxiety may even develop panic attacks.
bed bug A parasitic insect that feeds exclusively on blood. The common bed bug, Cimex lectularius, sucks human blood and is mainly active at night. The insect’s bite can cause skin rashes and welts that sometimes look like a mosquito bite, but different people react in different ways
Chagas disease A potentially life-threatening disease that afflicts about 6 million people, mostly in Latin America. It’s caused by a protozoan parasite and is usually spread by contact with the feces of an insect called a “kissing bug.” Untreated, it can kill by destroying the heart muscle and its nervous system.
exterminator A person whose job is to control or kills insects, rodents, and other pests. Sometimes also called a pest controller or a pest control operator.
feces A body's solid waste, made up of undigested food, bacteria and water. The feces of larger animals are sometimes also called dung.
germ Any one-celled microorganism, such as a bacterium, fungal species or virus particle. Some germs cause disease. Others can promote the health of higher-order organisms, including birds and mammals. The health effects of most germs, however, remain unknown.
inflammation The body’s response to cellular injury; it often involves swelling, redness, heat and pain. It is also an underlying feature responsible for the development and aggravation of many diseases, especially heart disease and diabetes.
insect A type of arthropod that as an adult will have six segmented legs and three body parts: a head, thorax and abdomen. There are hundreds of thousands of insects, which include bees, beetles, flies and moths.
insecticide A poison applied to kill insects.
insomnia An inability to get to sleep and stay asleep long enough to become fully rested.
parasite An organism that gets benefits from another species, called a host, but doesn’t provide it any benefits. Classic examples of parasites include ticks, fleas and tapeworms.