I have a World Of Warcraft question, can you help?

I was doing Deadmines the other day on my Death Knight to get the achievement and I noticed something strange. On the way to the entrance of the instance there is a bunch of miners, hard at work. The only problem is these miners are striking away with their picks then walking away with a bundle of wood!! This doesn't seem to make any sense to me. Does anyone know why they did this? Can you really mine for wood? Is Blizzard just being silly? My brain is going to explode if I dont get an answer!!!! LOL