On the basis of food habits, animals can be divided into the following types:

1. Herbivores

The term has been derived from the Latin words herba (herb) and vorare (to eat). The animals, which feed on plant only, are known as herbivores. Examples are goat, crow, buffalo,element, sheep, etc. Most herbivores feed on only one or a few plant species. Their diet may be some parts of the plant such as roots, leaves, seeds, sap and nectar. Some animals feed on algae or fungi. Many fishes eat diatoms (a group of algae).

2. Carnivores

This word has been derived from the Latin word carnis (flesh). The animals, which eat the flesh of other animals, are known as carnivores. They hunt and kill their prey and than feed on them; foe example, lion, tiger, leopard, etc. Although most of the carnivorous animals usually consume all parts of the bodies of their prey, some eat only certain parts such as skin, blood, flesh, etc.

3. Omnivores

This term has been derived from the Latin word omnis (all). The animal, which feed on plant as well as animal flesh, are known as omnivores. Examples are pig, domestic cat, crow, man, etc.

4. Carrion-eaters

The animals, which feed on foods which are already dead, are known as carrion-eaters. Vultures, hyena, kites are carrion-eaters. Many animals do not use plant or animal remains until they are broken into small fragments or detritus. Earthworm shows this mode of nutrition.


Certain protozoans like chilomonas, mastigamoeba show saprozoic mode of nutrition. They absorb dead organic matter in the form of solution through their body surface i.e., cell membrane. Some animal exhibit symbiotic nutrition. For example, certain protozoans and bacteria live as symbiont in the alimentary canals of cattle, rabbit, horse and termites. These help in cellulose digestion by secreting callulase enzyme. There are some animals such as frog and wall lizard that eat insects. Insect-eating organisms are called insectivores. There are some peculiar plants which are photosynthetic as well as holozoic. These are insectivorous plants such as sundew, pitcher plant Venus flytrap, etc.

In Venus flytrap when the insect lands on a leaf, the two havals snap together with spikes interlocking. After digestion and absorption, the leaf opens and the undigested remains get blown away.

1. Take a cup of boiling hot milk. Add a few drops of lemon. Stir the milk and watch what happens. Remember that milk is spilt inside the stomach into solid and liquid part. The solid portion is digested later on.


2. Eat a spoonful of sugar when you are extremely tired. Do you feel any change? Remember that sugars are quickly absorbed in the blood stream and can be easily available for liberating energy.