And they found that it was a headache, that there were problems that one species was interfering with or eating the other one and or stepping on ’em and that sort of thing. I remember the oxpeckers never worked that well. They were great to see ’cause they’re beautiful birds, but rhinos and elephants in captivity don’t get enough external parasites to keep them happy. So that was one problem that came up with that. So there was kind of growing awareness. There were experiments that were tried and some embarrassing consequences. And that kind of evolved. And there are things that you can do that you can get away with.
