All animals breathe in order to stay alive. They take in oxygen and give out carbon dioxide. Different animals take in oxygen in different ways.
Through Lungs:
Mammals, birds and reptiles breathe through their lungs. They have two lungs that are connected through a breathing tube to the nostrils. Air enters the body through the nostrils and fills the lungs. The lungs take in oxygen from the air and give out the carbon dioxide.
Through Skin:
An earthworm breathes through its skin. A frog breathes through its skin in water, while on land, it breathes through lungs.
Through Gills:
Fish,a baby frog or a tadpole and other aquatic animals breathe through gills. They take in water through their mouth. As the water passes through gills,oxygen dissolved in water is absorbed and carbon dioxide is released.
Through Body Holes:
Insects breathe through tiny holes present on their body. These holes are called spirals.The spirals are connected to the network of tubes called breathing tubes or trachea.The air enters the spiracels, passes through trachea and get absorbed by the tissue of the body. Carbon dioxide from the tissues enters the trachea and gets removed from the body through the spiracels.
