* Predation: When one animal hunts and eats another animal, it is known as predation. Predation can have a number of effects on the prey animal, including death, injury, or stress.
* Competition: Animals that live in the same environment and use the same resources are in competition with each other. Competition can lead to a number of negative effects for both animals, including reduced access to food, shelter, and mates.
* Mutualism: Mutualism is a relationship between two different species that benefits both species. For example, some animals provide food for other animals in exchange for protection.
* Commensalism: Commensalism is a relationship between two different species in which one species benefits from the relationship while the other species is neither harmed nor benefited. For example, some animals eat the leftovers of other animals.
* Parasitism: Parasitism is a relationship between two different species in which one species (the parasite) benefits from the relationship while the other species (the host) is harmed. For example, some animals live on or inside of other animals and feed on their blood or tissues.
The effects of animals on each other can be both direct and indirect. For example, predation can directly affect the prey animal, but it can also indirectly affect other animals that depend on the prey animal for food. Competition can also have both direct and indirect effects. For example, competition between two different species can lead to reduced access to food for both species, but it can also lead to the extinction of one of the species.
The interactions between animals are complex and ever-changing. As the environment changes, so too do the relationships between animals. This can make it difficult to predict how animals will be affected by each other in the future.