Researchers believe they've discovered a scientific explanation for the bizarre circular patches of bare land called "fairy circles" in the grasslands of Africa's Namib Desert. Guesses in the past have included a grass-killing gas that evaporates through the soil, to insects. The most recent study find the patches may be the natural result of the subsurface competition for resources among plants.

Grasslands there start off growing equally, but low levels of rainfall and nutrient-poor soil can cause intense competition between the grasses. The new theory postulates that strong grasses sap all of the water and nutrients from the soil, causing their weaker neighbors to die and a barren gap to form in the landscape.

The vegetation gap expands as the competition ensues, and the grass-free zone becomes a reservoir for nutrients and water. With the extra resources, larger grass species are then able to take root at the edge of the gap, and a stable fairy circle develops.

Fairy circles have been a mystery to scientists for decades. Last year, researchers  discovered that small barren areas last for an average of 24 years, while larger circles can last for up to 75 years. However, his research failed to resolve why the circles form in the first place, or why they mysteriously disappear.

Earlier this year, a University of Hamburg biologist claimed to have found evidence of termites creating the fairy circles. Essentially, he discovered colonies of the sand termite, Psammotermes allocerus, were nearly always found in the centers of fairy circles, where he also found increased soil moisture. He reasoned that the termites feed on the grasses' roots, killing the plants, which usually use up the soil's water, and then slurp up the water in the resulting circular patches to survive during the dry season.