Explain the difference between "sick" and "healthy" animal behavior.

The distinction between "sick" and "healthy" animal behavior is primarily characterized by observable traits that reflect an animal's overall well-being. Sick behavior typically manifests through signs such as lethargy, which indicates a decrease in energy levels and activity. Animals that are unwell often exhibit a lack of interest in food, resulting in reduced or absent appetite. This contrasts with healthy animals, which are generally active, sociable, and exhibit normal feeding behaviors.

The behaviors associated with a sick animal are clear indicators of illness and stress, prompting a need for medical attention. In comparisons, healthy animals engage with their environment and show curiosity and playfulness, demonstrating a typical baseline of vigor and health. This comparison highlights how behavioral signs are critical in identifying health issues in animals.