I think this instinct is built into them, because they are always acting like they are protecting their nests for dear life.
Elephants are poached for their ivory, the material found in their tusks, and they reproduce very, very slowly, so they are always in danger. Raccoons, on the other hand, are one of the animal species that have exploded in number, thanks to us humans. We enable them to have all the food they want, so their populations just get higher and higher. Emus are kind of a funny story. There used to be huge packs of emus that would roam the outback in Australia, and these packs would destroy farms they came across. Finally, the Australian government decided they would send a couple soldiers out to hunt the emus. Every time they would track down the emus that numbered in the thousands in each of these packs, they would get one or two and the rest would run off. After about a year, this was declared the Emu War, and with the emu losses only being a couple hundred within the year, it was quite the failure. In short, Australia declared war on emus and lost. The emu population is just fine.
