I always took the Line to mean you cant catch him cause he had a vasectomy cause that makes sense. but in light of this thread I think somone needs to gie Mr. Tyler a call.
California National Primate Research Center :
An example of a common animal test that has been replaced with new technology is the so-called “rabbit test,” an early form of pregnancy test. In the early 1920s, scientists discovered that a woman produces a hormone, called human chorionic gonadotropin (hCG), soon after becoming pregnant. They also found that rabbits injected with this hormone displayed distinct changes in their ovaries, and thus the “rabbit test” was born. In the early tests, the rabbits were euthanized so their ovaries could be examined; later refinements to the test enabled the rabbits’ lives to be spared.
University Health Systems of Eastern California :
In the past, pregnancy testing involved injecting a sample of a woman’s urine into an animal (such as a rabbit). Shortly afterward, the animal was sacrificed and its organs were examined for signs that hCG was present. However, pregnancy testing no longer requires the use of an animal to detect hCG.