Now that is interesting, I love Genesis and have studied it extensively (My favorite book), and love every year when we get back around to it but it's never long enough though, especially for the first few chapters to be in one week! Anyway that never dawned on me! yes he was given the dominion over them, why didn't he tell him to shut it? Hmm that's one to seriously contemplate, thanks Ivy!
Just a quick thought and I'm tired here so it might not make much sense but may be a factor to consider.
At that time in the whole wide world there was Adam, Chavah, The L-RD and the animals. The L-rd spoke to Adam, how often we don't know, but was he the only one? I don't think that any of the other animals could speak (only one other is the donkey of Balaam's) so maybe he was so fascinated that one of these animals he had been given charge over
could speak. And not only speak but seemed to know the mind of G-d, maybe Adam thought this creature was given more info than he , Adam had been. ..................Just some sleepy thoughts.