Rats Under the House, or Environmental Archaeology in Action

Today we were digging a shallow pit feature full of brick rubble on the newer part of our site, which dates to around 1820 to 1920. I think this was the remains of a brick pier from which all the usable brick had been robbed. Robbed foundations are a common feature of archaeological sites, and they are usually full of the broken pieces the "robbers" -- I would prefer "recyclers" -- left behind. (Above, Emily starts digging a similar feature.)

But when we removed all the rubble and the dark pit fill, we did not find clean subsoil. The soil under the bricks was obviously disturbed, spotted with gray stains. We messed around with this for a couple of hours, before we discovered that this effect had been created by tunneling. The ground under this brick pier (if that's what it was) was shot through with tunnels and cavities. My first thought was groundhogs, the great diggers in this part of the world, but these tunnels are too small.

Then we found these bones. I am no expert on rodent bones, but I suspect these are a lower jaw and broken skull of Rattus norvegicus, the brown rat. So these were rat tunnels. And that reinforced the argument that this feature was a building foundation, because on a farm rats almost always live under buildings.