Bright red pests barely larger than a tip of a pin have been invading Lawrence the past few weeks, but they’re nothing new.

Predaceous mites, the big name for the small insects, are most common in early May. They begin developing in the fall, when eggs are laid in cracks of building foundations. In the spring, those eggs hatch, and the tiny insects crawl into homes or offices, usually hanging out on windowsills or curtains.

“They’re just nuisances,” said Esau Formusoh, an entomologist and owner of EcoPest.

They won’t bite and aren’t dangerous. If you squish them with your finger, they leave behind a red stain.

Usually found on sidewalks and around bushes on the south side of a building, they will start to disappear once temperatures reach well into the 80s.

“Every insect has their own cycle when they come out,” Formusoh said. “When it gets really hot, you’ll stop seeing them.”

The tiny pests feed off other, even smaller insects and insect eggs outside building foundations.

If predaceous mites are too much of a nuisance, Formusoh suggested treating the grass and plants around a building’s perimeter. But he said indoor treatment wasn’t necessary because the tiny red mites will die because of a lack of food.