<P> Formication is etymologically derived from the Latin word formica, meaning "ant", precisely because of this similarity in sensation to that of crawling insects . The term has been in use for several hundred years . In the 1797 edition of the Encyclopædia Britannica, a description of the condition raphania includes the symptom: </P> <P>... a formication, or sensation as of ants or other small insects creeping on the parts . </P> <P> Described again in an instructional text from 1890: </P> <P> A variety of itching, often encountered in the eczema of elderly people, is formication; this is described as exactly like the crawling of myriads of animals over the skin . It is probably due to the successive irritation of nerve fibrils in the skin . At times patients who suffer from it will scarcely be persuaded that it is not due to insects . Yielding to the temptation to scratch invariably makes the disease worse . </P>

What causes your skin to feel like its crawling