Tumbleweeds

Tumbleweeds are world objects in Fallout: New Vegas.

Characteristics
In Fallout: New Vegas, tumbleweeds appear as balls of wheat-colored weeds which roll around the Mojave Desert. Often they can get stuck on things, such as the buildings of Goodsprings.

Tumbleweeds always travel west which could imply that there is a slight westward breeze in the Mojave Wasteland.

A tumbleweed is very light, so shooting it will make it fly several feet. Because a shotgun shoots many pellets at once, even more for the sawed-off shotgun, shooting it with one will commonly send the tumbleweed flying into the sky so far that it usually disappears from sight before it can be seen landing.

If you jump on top of one (you might need to wedge it in between some props to do this) it strangely makes the same noise as walking on a metallic platform.

Behind the scenes

 * A radioactive version of the tumbleweed exists within the resources of Fallout: New Vegas, but remains unused. Identified as Radioactive Tumbleweed, it emits radiation similar to a glowing one, is classified as a creature, consequently moves under its own power, and can be killed.
 * These versions of the tumbleweed were cut due to the bugs they introduced (and ending up in weird places).
 * The radioactive tumbleweeds were inspired by the tumbleweeds in Hanford, Washington, which would soak up radioactive elements in the ground water, dry up and blow away.
 * The Fallout: New Vegas Official Game Guide Collector's Edition refers to these cut environmental dangers being at the Crescent Canyon, and Mesquite Mountains Crater.

Bugs

 * Occasionally tumbleweeds may be found frozen in place almost as if they were scenery, particularly around Novac. Just as before, jumping on top of them yields a metallic sound.