I think we need to change the phrase "breed like rabbits" to "breed like humans," as no other species on this planet even comes close to the human reproduction rate. As our population grows, available land shrinks and more and more people are forced to live in crowded, urbanized environments, a situation ripe for the easy spread and emergence of infectious agents.
As a child, I helped others by volunteering with an animal shelter, giving away my old clothes and being kind to my schoolmates. As I grew, my circle of compassion expanded to include more and more individuals in need. Among all the issues in the world, I found the plight of nonhuman animals particularly compelling.