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.
Some hummer's bills are longer than their bodies. Hummingbirds' diets are made up of insects as well as nectar from flowers. The length of a hummingbird's bill doesn't interfere with catching protein-rich insects, as the bird'll simply fly toward a bug with his bill open. But the length is useful for reaching deep into blossoms to lap up nectar.