Animal Behavior 

The tail flick assay is a test that is used to measure pain response in rodents. The tail of the rodent is subjected to a heat source. Once the rodent feels pain, it quickly removes its tail which is known as the tail flick. This test is usually used to test the effect of pain killers on rodents. Many researchers give rodents a dosage of a pain killer than they are testing and measure their tail flick response to see if the rodent takes longer to flick their tail in response to the pain killer. A common drug that was measured in this test is morphine. 

A main concern/though that I had while researching this test is the ethics of the test. I do not think that it is ethically to subject an animal to pain for human research. Although the rodent is freely able to flick away its tail once it feels any discomfort, it does not seem ethical to continue to subject the rodent to the pain. In addition most researchers want to find a treatment for chronic pain not acute pain, which is what the rodent is displaying.