We haven’t done it to very many species, and the ones we did it to were of very low-order species such as plants and fungi.  Ethics forbids us from doing it to anything much more complex than that, so instead we taught some chimpanzees to do it in exchange for a variety of differing treats.  Getting simians to perform tasks of varying complexity for varying rewards IS ethical, getting a grant for it is orders of magnitude easier, and most great apes don’t have such developed ethical standards.  So long as we publish the results of their sieve-grinding as a sub-topic of the “work for treats” papers, we can more efficiently gather data while avoiding ethical conundrums.

Oh my goodness

Help. My (37F) morally dubious experiment chimpanzee’s (14F, 18F, 22M, 23F, 36F, 36M) have formed an ethics board.