This is a cast of a fire ant colony which also had larger tunnels running through it likely made by ground squirrels. No squirrels were harmed in the making of this cast. So much aluminum went into these larger tunnels that there wasn't much aluminum left to flow into the actual colony. As a result, much of the ant colony itself was not cast. I still find it very interesting. It's extremely massive at 22.4 lbs and 27" at its widest. The rodent tunnels are around 1.5" min diameter on average but are several inches wide at some points. The longest tunnel on the right is around 15" long. The fire ant colony structure that you see is the part of the colony that was about 1 ft. underground, and any of the colony structure above that was not cast.