Frustrated students and residents throughout the area are brushing off their arms and swatting the air, trying to steer away the swarm of ladybugs that seems to be everywhere.

“They’re all over my windows, all over the ceiling,” said Mariola Janik, an Education sophomore.

The unexpected warm weather has encouraged the bugs to search for a comfortable winter home, said Tom Tiddens, supervisor of plant healthcare at the Chicago Botanic Garden.

Referred to as multicolored Asian lady beetles by experts, Tiddens said the species was imported from China and released in the southeast United States in the 1980s as a natural form of pest control.

The bugs eat a soft-bodied insect, called aphids, which destroy important crops such as soybeans, Tiddens said.

The insects cause more benefit than harm, even if they appear in large numbers, he said.

“It’s really just one small period in fall that they become a nuisance,” he said.

Weinberg junior Thomas Kluz from Wheeling, Ill., said he has never seen an infestation of this size in the Chicago area.

“I’m from around here and I’ve never experienced a crazy amount like this before,” he said.

The species has no natural predators in the United States to check the population, said Philip Parrillo, an entomologist and insect collection manager at the Field Museum.

More competitive bugs are taking away the native food supply and native species populations are shrinking as imported populations grows.

Not only are the foreign lady beetles a pain for fellow bugs, they bite.

“Unlike our native species, these guys are big enough where they can actually get a piece of skin between their teeth and nip you,” Parrillo said.

In the fall the beetles form large swarms because their behavior cues change, Parrillo said. Although it’s impossible to predict where they will gather, the bugs are attracted to highly reflective surfaces, he said.

Although the sudden appearance of the lady beetles isn’t a new phenomenon, it’s a situation that’s growing worse, he added.

McCormick senior James Diomede said he’s seen a large number of lady beetles come every fall since he’s been at Northwestern.

During his first two years at NU, he said he saw them form large clumps like nests under windowsills at 1835 Hinman dorm.

But Diomede was unfazed by the bugs.

“It was nice to see them out,” he said. “They’re pretty.”

The lady beetles will stay as long as the warm weather lingers, Parrillo said.

“As soon as it starts getting cold again, bang, they’re gonna hunker down for the winter,” he said.