ELI5: Explain Like I'm 5

why are animals altruistic?

Altruism is when an animal does something that helps another animal, even if it means that it gets nothing in return. Animals can be altruistic because helping others makes them happy and part of an animal family. It's also a way of learning and teaching. By doing something that helps another animal, the animal learns something new, and it can also help the other animal learn a new skill. Altruism is also a way of showing a bond and caring for each other. It's like saying "I care about you, and I want you to be safe and happy".