Yes.. Even [plants have been argued to have Buddha nature][1]plants have been argued to have Buddha nature... after all Buddha nature is all-encompassing, the root of existence and non-existence..
My perspective:
Nothing has Buddha-nature! Nothing but "Buddha-nature" exists.
Buddha nature is the Universe. The world, items and conscious beings are just constantly changing interdependent items bobbing around within it...
Bodhisattvas thus identify themselves as the whole universe and not just as a person. [1]: http://theendlessfurther.com/even-plants-and-trees-have-buddha-nature/