For Kids Birds Flashcards ১টি বক্সে ৩২টি পাখির জীবনী ইংরেজিতে রয়েছে। প্রি-প্রাইমারী শিক্ষার্থীরা পাখি সম্পর্কে অনেক তথ্য জানতে পারবে Hummingbird is the smallest bird in the world. There are 400 species of hummingbirds in the world. They can fly backwards. The smallest hummingbird species is 6 centimeters (or 2 inches). The largest hummingbird is 23 centimeters (or 9.1 inches).: Hummingbirds can flap their wings up to 90 times per second. They can fly at an average of 45 kilometers per hour. Hummingbirds cannot walk. They usually feed on flower sap. But it also catches and eats flying insects and spiders. Female hummingbird’s usually lay 2 white eggs at a time while it flying. Before that egg falls from the sky to the ground, the baby is born from the egg and flies away. Their average lifespan is 1 to 2 years.