Causes and symptoms. Fatigue may be the result of one or more environmental causes such as inadequate rest, improper diet, work and home stressors, or poor physical conditioning, or one symptom of a chronic medical condition or disease process in the body.
1 A hummingbird will use its tongue to lap up nectar from flowers and feeders. 2  A hummingbird's tongue is grooved like the shape of a W. 3  Hummingbirds have tiny hairs on the tip of the tongue to help lap up nectar.
In the wild, they survive from 5 to 7 years. Hummingbirds feed on nectar or tiny arthropods from flower blossoms, especially when feeding their young. In order to consume as much nourishment as they do, they must visit hundreds of flowers daily as they are only hours away from starving.