The length given in the stats (17") includes the long foraging tunnel which is about 7" long form the main body of the colony.

When building displays, typically smaller casts can be bolted directly to the wood base by tapping threads into the aluminum. This is not always viable for larger casts since the weight tends to put too much stress on the wood. This cast is a hybrid mount. It was slightly too heavy for just a bolt, so it was bolted and also a wood dowel was used to prevent it from being able to sway and break the wood.