The document discusses laboratory animals and their use in biomedical research. It states that rodents like mice and rats are most commonly used as they are inexpensive and easy to care for. Ideal laboratory animals must be bred and housed in rigorously controlled environments. Proper housing, management, sanitation and environmental conditions are required to ensure animal welfare and quality research data. Common laboratory animals include mice, rats, hamsters, guinea pigs and others. Rodent breeding procedures aim to provide offspring for research according to investigators' protocols.