Illinois Is Currently Covered In Swarms Of Ladybugs–Here’s Why

When I walked out on to my backyard patio over the weekend, I was treated to the sight of my wife and our two dogs behaving somewhat strangely. That, in and of itself, is not that unusual, but the way they were acting was.

My wife was waving her hands around her head in a very distinct "Shoo" pattern, normally reserved for bees and/or mosquitoes, and the dogs were whipping their heads around frantically trying to understand why all these little red, orange, and yellow bugs with polka-dots were landing on and crawling all over them.

Being a keen observer, I said something to the effect of "what's going on out here?" and got "freaking ladybugs are everywhere!" as my answer, followed closely by "what's with all the !#@%&! ladybugs?!"

The Word "Swarm" Really Doesn't Give Off A Very Pleasant Feeling, But If I'm Going To Be Swarmed, I'd Much Prefer Ladybugs To Other Unpleasant Things Like Wasps, Mosquitoes, Bill Collectors...

Putting swarm preferences aside, let's get to the reasons that there are so many ladybug swarms going on throughout the state, especially Northern Illinois.

News.WTTW.com:

Where native ladybugs will largely spend the winter snuggled up under leaf litter or in other outdoor hidey holes, Asian lady beetles have a tendency to wander indoors. And where there’s one, more will follow, thanks to some combination of visual and chemical cues.

Researchers in Ohio showed that lady beetles’ hunt for an over-wintering site is triggered by a particular sequence of temperature changes: a period of cooler weather, followed by sunny days that warm up to at least the lower 60s.

Chalk it all up to seasonal behavior. Winter is approaching, so the ladybugs/lady beetles are searching for a warm spot to spend the winter, and your house is among their top picks. However, a sunny, warm day causes them to pause their house hunting to soak up a bunch of sunshine and warmth.

Later This Week, Temperatures Will Begin To Fall And The Ladybugs/Lady Beetles Will Be Done Swarming And Go Back To Looking For Ways To Get Into Your House For The Winter Months

The multi-colored lady beetles are considered to be a beneficial predator that eats aphids and other pests that can damage fruits, vegetables, and other agricultural crops, but they're also considered to be a nuisance because of their habit of invading your house.

FarmersAlmanac.com:

Bottom line—the ladybugs are getting the last bit of warmth and mean no harm. Ladybugs are friends of the garden. They feed on insect eggs, small worms, aphids, and other pests. They can, however, damage carpets and furniture with their secretions. And if your home is really infested, when they die they can be all over window sills throughout the house. Best way to get rid of them? Vacuum.