What is the main effect of overpopulation on animals? More animals are used for food. Extinction occurs due to loss of habitat. A change in the animal population harms the environment. Social conflict occurs due to limited resources.

The main effect of overpopulation on animals is extinction occurs due to the loss of habitat. The human population and the animal population will always be at odds with one another. The greater the number of people that there are, the more space they need to live. As a result, the people take over the animals' habitat and the less space the animals have, and the more their habitat is destroyed, the greater impact it has on the animals and their habitat.