Different Life Styles is another important topic to learn. Following are some noteworthy points to remember.

Breathing in Animals

• Animals breathe in oxygen and give out carbon dioxide.
• All mammals, birds, reptiles, adult amphibians and human beings breathe through lungs.
• Human beings have two lungs on either side, each lung has tubes within them called bronchi.
• The blood comes to the heart through tiny blood vessels called capillaries.
• Insects have a special opening called ‘spiracles‘. These openings lead to a system of tubes and trachea.
• All aquatic animals like fishes, prawns, and crabs breathe through gills.
• The gills lie under the operculum on each side of the head.
• Single-celled animals, like the amoeba, breathe through the general body surface.
• A tadpole (baby frog) breathes through gills whereas an adult frog through lungs on land and through moist skin under water.

Feeding Habits in Animals

• Herbivores: Plant-eating animals are called herbivores.
  Example: cow, goat, buffalo, deer giraffe, etc. eat green plants.
• Carnivores: Flesh-eating animals are called carnivores.
  Example: lion, cat, tiger, etc.
• Rodents: The rodents gnaw their food.
  Example: rat, rabbit, squirrel, etc.
• Omnivores: Animals which feed on both green plants, as well as the flesh of other animals, are called omnivores.
  Example: human beings, crow, bear, etc.
• Birds such as hawk, owl, eagle, and kite have sharp hooked beaks and claws to catch and tear the flesh.
• Birds like sparrow have short and strong beaks for crushing seeds.
• Insects like cockroaches and grasshoppers have strong biting and chewing mouth organs.
• Mosquitos have piercing mouth organ for sucking.
• Houseflies have a spongy pad-like tongue.
• Butterflies & bees have a long coiled sucking tongue or tube called proboscis.
• Amphibians like frogs have a sticky tongue for catching insects like flies, beetles, and worms.

Movement in Animals:

• Man, monkeys, apes, gorillas and many other animals of this group use their forelimbs for catching, holding and eating the food or gripping anything.
• Fishes move with the help of their fins.
• Frogs have webbed toes for swimming in water but on land, they use their long hind legs to jump.
• Reptiles like lizards, tortoises, crocodiles have limbs to move whereas snakes have no limbs, they crawl on the ground with the help of scales on their body.
• Insects crawl by means of their legs.
• Insects have three pair of legs.
• Insects living in water use their legs as oars while swimming.
• Most insects have wings but they are very different from those of birds.
• Lice, bugs, and termites have no wings at all.

Migration among Animals:

• To avoid the unfavourable climatic changes, some animals migrate from one place to another and come back to their original homes. This sort of movement is known as migration.
• ‘Arctic tern’ is the greatest migrator, it flies more than 30,000 km from the Arctic to the Antarctic and back to the Arctic again. (to watch a related documentary on youtube Click Here)
• The eel is one of the best known migratory fishes.
• Locust is the most dangerous of migratory insects.
• The monarch butterfly migrates from Canada to Mexico.