I've been finding a lot of these small wooden pegs on the railroad tracks near where I live. I have no idea what they are. They look old. I photographed it next to a CD 145, so that you can get an idea of how tall the peg is. It's the exact same height as the insulator. These wooden pegs have no threads on them at all. There are very many of them, up on the tracks where I live. Can anyone help me to identify them ?

Update: Railroad workers would occasionally drill into railroad ties and telegraph poles to check for wood-rot. If they determined that the tie or pole was still usable, they would hammer these small pegs back into the drilled holes to prevent rotting.