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.
They can also hover in mid-air, fly sideways and even upside-down. Â· Wings: A hummingbirdâs wings beat about 70 times per second (200 times per second when diving!) Â· Feeding: Hummingbirds are big eaters, eating over twice their weight every day! Their diet consists of both nectar and flying insects.