• Different types of birds use feathers in different ways.feathers image by Rachel from Fotolia.com
  
  Any animal with feathers is considered a bird, according to the Fernbank Science Center. This includes animals that fly, such as hummingbirds and most parrots, as well as those that don't, such as penguins and ostriches. While feathers don't serve the purpose of flight in all birds, they're all made the same way. You can use projects to experiment with how feathers are useful to all birds in different ways.
  
  

Examine How Barbules Hook Together

• Bird feathers have a special design to them that enables birds to withstand air resistance in flight, according to PetEducation.com. Each section (called barbs) of their feathers is made up of tiny hairs called barbules that hook together to make the whole feather strong. In this simple project from Home Science Tools, kids will closely examine these barbules. Provide kids with a bird feather and a magnifying glass. Point out that if they hold the feather between two fingers and move their fingers inward, toward the vein in the feather, kids can see each barbule begin to separate. They'll probably need the magnifying glass to really see this. Kids will then hold the feather in the same way and move their fingers outward, away from the vein, and observe as the barbules hook back together.
  
  

See How Feathers Help Ducks Float

• If your kids have ever wondered why ducks are able to float, they might be interested to know that much of it has to do with the duck's feathers. For this project idea from Kaplan Tutoring, you'll start by showing kids that oil and water don't mix, which means oil will float on the surface of water. With this knowledge, ask kids what they think might happen if a bird's feather is covered with oil. To experiment with this, kids can cover a feather with oil or petroleum jelly and put it in a bowl of water. They'll notice that the feather just floats. They can then wet another feather and put it in a separate bowl of water and watch as the feather sinks. You can then explain to kids that ducks sometimes scratch at a gland in their skin with their beak so that oils from the gland will cover their feathers, enabling them to float.
  
  

Test Feathers As A Source Of Insulation

• Though they may seem thin, feathers are actually a useful source of insulation for ducks and birds. In this experiment from The Biology Corner, kids will test the insulation of feathers against some other materials. You'll have kids fill a glass with water and place the glass in the center of a bowl. Place a thermometer in the glass to gauge the temperature of the water, then add ice to the bowl in the area around the glass. Record the drop in temperature.
  
  Experiment with various means of insulation, such as cotton fabric, feathers, paper, and other materials by wrapping the items around the glass and covering the outside completely (one material at a time). To do this, you'll remove the glass and wrap the material around it. You can then wrap the whole glass -- insulation included -- in plastic wrap both to hold the material in place and to protect the material from the ice. Observe how quickly the water temperature rises when the glass is insulated and see how the feathers compare to the other materials.