That unusual dirt structure rising from the floor is most likely a termite shelter tube, sometimes called a mud tube or exploratory tube. Subterranean termites build these structures from soil, saliva, and tiny bits of debris so they can travel while staying protected from dry air and predators. Most termite tubes run along walls, foundations, or wooden beams, but occasionally termites build free-standing or hanging tubes that can look like bizarre little towers.

Finding one indoors is worth taking seriously because the visible tube may be only a small part of a much larger hidden colony. Termites often remain concealed inside walls, flooring, crawl spaces, or wooden framing while feeding on cellulose-containing materials. The tube itself doesn’t prove extensive structural damage has already occurred, but it does suggest termites may be actively exploring or traveling through the area.

It’s usually better not to simply scrape the structure away and forget about it. Breaking the tube may temporarily disturb the insects, but it won’t eliminate a colony living underground or inside the building. Look nearby for other warning signs such as hollow-sounding wood, blistered paint, discarded wings, tiny openings in wood, or additional mud tubes along the foundation.

If you find something like this inside your home, having the property inspected by a qualified termite or pest professional is the safest next step. Treatment depends on where the colony is located and how far it has spread.

So that strange “dirt tower” isn’t just an unusual pile of soil. It may be a termite-built tunnel—and an early warning that something is happening where you can’t easily see it.