its a male.
i dont really know how and i dont want to know, i guess the nooks and crannies just fill up with dirt over time until it eventually gets ejected.
basically when you probe them to determine the gender and the probe goes in much deeper on either side when its a male.... and then imagine filling all that with gypsum which solidifies.... thats what you get. except that instead of gypsum its some groce mix of different things, including shed.
yes its called sperm plugs.