My dad did the same thing with tapioca, but he told me they were fish eyes! Also, he took it a step further — he was kind of a Peter-Pan-grownup-kid kind of dad who was notorious for pranks, so after he got home from a fishing trip one time, he cut out and saved a couple of the fish eyes and hid them in the freezer. A while later after we made a big bowl of tapioca pudding at home (or someone brought it over? I can’t remember), he took the fish eyes and put them right in the middle of the bowl on top of the pudding. I will never forget how upset I got.