Brian Forschler, professor of entomology in the College of Agriculture and Environmental Sciences, spoke with CNN about ways to keep ladybugs from homes during the cold months.
As temperatures start to drop, ladybugs gather indoors to stay warm. According to Forschler, they are attracted to lighter areas with dark features such as a crevice or crack in a south-facing wall or window illuminated by sunlight.
After finding a comfortable spot for the winter, the bugs will leave a chemical marker that acts as a calling card for other ladybugs.
While the most harm ladybugs can wreak is in their bite, the bites don’t feel any worse than a pinprick, Forschler said, making them almost harmless.
When removing ladybugs, there are best practices. If agitated or disturbed, they may have a defensive reaction known as “reflex bleeding” in which they release foul-smelling liquids that can stain drapes or clothes.
Forschler said the best way to avoid this reaction while removing ladybugs is to vacuum them up and dispose of them.
To keep the ladybugs from returning, clean the spot the ladybugs aggregated with vinegar or ammonia-based cleaners, removing the chemical marker used to attract more ladybugs. It also helps to use caulk to seal up the crevices or cracks that the ladybugs used to enter.
“Removing the pheromone might reduce the number that ‘decide’ to spend the winter at that site, (but) it probably won’t stop them as well as sealing the cracks and crevices on that side of the building,” said Forschler.
While ladybugs may be a nuisance, getting rid of them may not be worth the hassle.
“Keeping them out is entirely possible, but hardly practical,” said Forschler. “If you can convince people not to worry about (the ladybugs), that’s huge.”