DNA barcoding
Another good thing about DNA barcoding is that scientists do not need to get close to the animal or plant they want to study.  This is good for studying animals that are easily damaged, very shy, or dangerous to humans.  The scientists do not even need to see the organism to use DNA barcoding.  In one study, scientists collected feces (poop) from an African savanna.  They used DNA barcoding to tell which species of animal had left it there and which plants it had eaten, all from the undigested DNA.