This document discusses experimental laboratory animals used for research. It describes mice, rats, guinea pigs, and rabbits as the main types of laboratory animals. Mice make up 80% of experiments and are used for toxicology, cancer research, and studies of diseases like diabetes. Rats are also commonly used and studied for behavior, insulin research, and toxicology. Guinea pigs are used to study allergies, nutrition, and safety testing. Rabbits are employed for antibody production, radiation studies, and testing drugs, insulin, and viruses. In closing, the key roles of laboratory animals are listed as pharmacology, toxicology, physiology, surgery demonstrations, disease research, and pregnancy/immunity experiments.