The correct answer to this question is for a fact true!
When and why this happens is because the members of that population get desperate (like limited supply of food, water, mates, or even habitats) so at that point of the situation all the creatures of that population are so desperate that they are willing to do everything and anything to survive. And then it becomes competition. That's one of the things that these 2 phrases are used for mainly: "Every man is for himself" "Survival for the fittest"
That is the answer to your question! If you need help with any other questions, just let me know and i will do my best to help you!
