Our baby didn't constrict his first pinkie he ate with us, but the second one he went to town. He seemed totally disinterested in the pinkie in his feeding tub so I picked it up with the tongs and danced it around. He struck so fast, and then constricted for a while, then figured out he needed to move off the arm and onto the head to eat the little guy.
I find the whole thing fascinating. Now I just wonder when he will finally poo...