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.
Mostly nectar and insects. Takes nectar from flowers, and will feed on tiny insects as well. Favors red tubular flowers such as penstemon, red monkey-flower, red columbine, paintbrush, scarlet sage; also flowers of other colors, such as the yellow blooms of tree-tobacco. Will also feed on sugar-water mixtures in hummingbird feeders.