- Their eyes can move independently, helping them monitor the vast range of their environment while hovering.
- Migration routes are learned behavior; each generation teaches the next their migratory paths.
- They have an excellent memory for locations, remembering every flower they have visited.
- The smallest species weighs less than a penny.
- Legs are weak and only useful for perching and moving sideways while clinging to branches.
- They cannot walk or hop, which is an unusual trait for a bird.
- Their breathing rate can increase from 250 breaths per minute to over 600 during intense activity.
- They are the only birds that can generate lift on both the downstroke and upstroke of their wing beats.
- Their bones are pneumatic (filled with air), making them lighter and more buoyant in flight.
- Due to their size, they have few natural predators.
- Their presence is often symbolic of joy and energy in many cultures.
- They can recognize and remember individual humans, especially those who refill feeders regularly.
