In the world of nature, a parasite feeds on some other living plant or animal. We also can use the word to describe certain people. A human parasite is too lazy to make his own living. He prefers to eat at someone elsets expense and do nothing in return. Of course we cannot use this word to describe sick people or children. Papa provides the family food until the young people learn the thrilling job of making their own livings. What’s more, every sensible young person helps with chores and gives his parents respect and appreciation.
Mother Nature says that all her creatures must do the best they can to make their own living. A parasite breaks this rule, and sooner or later it pays a terrible penalty. It may be a plant or an animal, but it spends all or part of its life without doing anything to provide food, shelter or protection for itself. It lives off some other plant or animal which we call the host of the parasite.
A dog is usually pestered with a multitude of fleas. They are parasites which share the shelter of his warm coat and dine on his skin. He may become thin and nervous because a tapeworm has set up housekeeping in his stomach and dines there on the doggie’s dinner. A dog can be attacked outside or inside by some 40 different parasites. Birds are attacked by lice which lay eggs on their feathers and later bore under the skin.
Fleas and chiggers are blood suoking parasites and certain ticks can bite through even the tough skin of a rhino. Many blood sucking insects do double damage. The mosquito can carry the parasite germ of malaria and the bite of a flea can infect the host with the germ which causes bubonic plague.
Most animal parasites are small. The lamprey and the hagfish, however, are sizable parasites which use their round, sucking mouths to fix themselves onto host fishes. Many animal parasites feed on plants. Scale insects which damage orange trees, aphids which attack roses and roundworms which bore into potatoes are parasites.
Certain plants also live on plant or animal hosts. The molds and mildews that attack our fruit trees are plant parasites, so are the smuts and rusts. The mushroom type bracts which grow on tree trunks are also parasites and a field of clover may be attacked by the orange colored tangles of the dodder parasite. A parasite plant or animal must pay for its selfish laziness. It is usually very helpless and, if the host dies, the parasite soon perishes. For this reason, though a parasite is always dangerous, it does not usually destroy its host.
All the parasites, we are told, have descended from ancestors who were able to make their own living. When they chose to depend upon host plants and animals, they lost the ability to work for a living. Certain parasite animals have lost their eyes and ears, their feelers and even their legs. Mother Nature insists that her creatures keep busy or in time they will become unable to keep busy.