What terms are used to describe this behaviour?
"Body packers" or "mules" in the United States; "Stuffers and swallowers" in the United Kingdom; "Body packers" in Australia.
How high is the mortality from this activity?
Very hard to say, as who knows what the actual numbers are. Between 1975 and 1981 approximately half of all confirmed cases died due to packet rupture. Modern packers have presumably become more adept.
How much does the average packet of cocaine contain and what is the amount required to likely kill the body packer?
Each packet typically contains 3-12g of cocaine. 1-3g is usually fatal. Some body packers have been found with over 1kg of cocaine in the intestine.
CT scan of the abdomen demonstrates numerous colonic (mainly descending and sigmoid colon and rectum) hyperdense oval foreign bodies, consistent with packets containing a radiodense powder - most probably cocaine.