Although I might be a bit biased, I find homo sapien behavior very interesting. Their behavior is often times irrational and they also happen to be extremely territorial, which is a really bad combination if you ask me.
Homo sapiens have developed in a very fascinating manner over the years. For some reason, at one point in time, they even started to occasionally just kill themselves. They are a very aggressive species, sometimes even hostile towards their own kind.
Although the homo sapiens might be in the clear for now, there is a decent chance that they'll eventually kill off their whole race.