One of our first stops upon arriving in Litchfield National Park on our Northern Territory trip was an area where you could see tons of termite mounds. We had already seen several in Kakadu National Park and while driving all around the Northern Territory, but we hadn't seen so many in one place before. These structures are pretty fascinating. Termites feed on grass and plant debris found in areas that are flooded during the wet season, so they have to live above ground in the mounds. Inside the mounds are complex tunnels, arches, chimneys, insulation, etc.
Below is a picture of a cathedral mound made by woodland termites. Some of these were massive! In the Kakadu post, I am standing next to one, so you can get an idea of the height. These mounds are made of chewed wood, mud, and feces (yum). If humans made a similar structure, it would be over a kilometer high!
Who knew that termites did something besides eat wood and cause problems?!