As we know there are lower realms mentioned in Buddhism, like the animal realm.
If you have heard the story of the "Alavaka yaksha/yakkha" (He was an evil being by birth)
You might also think "If beings like "Alavaka" can reach goals in the path are they considered lower because they are evil by birth?"
After all he is not the only one of his kind to reach goals of the path on the spot where they learned Buddhism.As to Suttas/Sutras these beings serve as soldiers in armies of Gods/Devas, so they clearly aren't some primitive things like our animals.These beings also have ridiculous strength and amazing abilities like shape shifting.
So what i'm asking is...
Are they labeled Lower realm creatures because they are Bad or Evil from birth or is there any other reason?
(Please note that i am only asking about the Race/Species/Beings called Yakkha or Yaksha)