Predation is a biological interaction between two organisms predator and prey. The predator kills and eats the other organism. It is one of the ecological process by which energy is transferred from one organism to the other organism. Lions are predators that hunt and kill deer which are their prey. Predators camouflage themselves so they can hide. They have sharp claws and jaws for hunting.

The symbiotic relationship between different organisms where one organism called the parasite lives on the other organism called the host. In this type of relationship, the parasite depends on the host for food and shelter. The host gets no benefit from the parasite instead it is harmed by the parasite. Parasites are of different types- ectoparasites, endoparasites, obligate parasites, facultative parasites.

Litter is the undecomposed plant materials like leaves and twigs on the forest floor. It plays a very important role in forest ecosystems by adding fertility to the soil because decomposing litter releases essential nutrients to the soil. Abiotic (e.g. wind, water, soil, temperature, etc.) factors play important role in the decomposition of litter. It increases ecological productivity.

The animals that feed on the dead and decaying organic matter of plants and animals are called scavengers. They are one type of carnivores which is an organism that eats meat. Examples include vulture, eagle, hyena, carrion beetles, etc. Sometimes they hunt live prey to fulfill their requirements. They keep the ecosystem free from the bodies of dead animals and plants by consuming them. They play important role in the food web. They help to clean the environment. Two examples of scavengers are- Hawk Jackal

The organisms which eat primary consumers or herbivores for their energy are called carnivores. They tend to be larger and less in number. They are present in the middle of the food chain. Tertiary consumers depend on secondary consumers for their food. They can thrive in a wide range of ecosystems. The two examples of carnivores are- Snake Wolves