In mechanics, a force is that which causes a change in velocity or, if you prefer, that which causes an acceleration. When more than one force acts on an object it is the net force that is important. Since force is a vector quantity, use geometry instead of arithmetic when combining forces.
Quick Answer. A crawling sensation felt on the skin may be caused by a condition called morgellons, according to WebMD. Common symptoms of morgellons include feeling like bugs are crawling on the skin, burning, itching and stinging sensations. In some cases skin sores may appear as well.
The itching sensation is caused by the rising and falling of estrogen, the pregnancy hormone. 1  Increase in estrogen levels often spikes the itching sensation on the stomach and other parts of the body. 2  Sometimes, this may also lead to eczema, a severe skin disease.