The use of test animals in scientific experiments and research has been a controversial topic for many years. Researchers have been looking for synonyms for the term "test animals" to reduce the negative connotations associated with the use of animals. Some of the most commonly used alternatives to the term "test animals" include "experimental animals", "preclinical models", "laboratory animals", "research animals", and "animal subjects". These terms are used to highlight the valuable contribution that animals can make to scientific research. However, there are still ongoing debates as to whether animal testing is ethical and necessary, and alternatives like computer modeling and in vitro testing are being developed to reduce the need for such testing.