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.
Hummingbirds feed about 5-10 times per hour for 30-60 seconds each time. Hummingbirds feed through a long, tube-like tongue that darts into the flower's corolla for nectar. The tongue, shaped like a W, uses capillary action to absorb the nectar much like a paper towel absorbs water.