KNOXVILLE, Tenn. (WVLT) -- Have you seen little white floating things in the air? Maybe you've thought they could be seeds or even bugs? Local 8 News did some research to find out what they are.

The good news is they aren't too dangerous to plants, although they may make leaves look a little discolored.

The aphids create a large amount of honeydew, which makes a sticky mess and helps develop a blackish sooty mold on the area beneath infested trees.

For humans, experts say they are an invasive species originally from Asia called Asian Wooly Hackberry Aphids. They're mostly harmless—the biggest problem they present is when they float into unsuspecting human faces.

"It's actually a small little insect, maybe about a millimeter long, they look like a little tuft of cotton that grew wings and started flying around," said Sean Bowers, tree and shrub specialist.

The aphids may land on you, especially if you're sweating, but they don't bite or sting.

The University of Tennessee Institute of Agriculture said aphid populations vary from year to year and can be difficult to predict. One major factor that affects their appearance is weather.

The Asian Wooly Hackberry Aphid population builds on hackberry and sugarberry plants, which are common in Tennessee. Experts with UT said populations have been building since 2001, and their numbers appear to have spiked again this year.

Experts said next spring, drenching the base of hackberry and sugarberry plants with imidacloprid (Bayer Advanced Tree & Shrub Insect Control) will provide season-long control and may even control the population through the next spring.