At Hannover Adventure Zoo humans are not the only workers, there is also a diligent team of honey bees, from different honey bee populations, at the theme world Meyers Hof.
Actually, animal rights activists are concerned with all animals, from the great ape to the bee. In practice, their involvement is restricted to farm animals or animals which are kept by humans, ie to a very small percentage of the total of more than 1.3 million known animal species worldwide.