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.
metabolism of a hummingbird, he would have to eat 285 pounds (129 kg) of meat every day to maintain his weight. Hummingbirds can be aggressive and have been known to attack much larger birds including jays, crows, and even hawks. Commonly asked questions about hummingbirds Hummingbird drawings courtesy of Dr. George C. West HUMMINGBIRDS of