Gleaming crimson ladybugs adorned with ebony spots are undeniably charming, but if they decide to gather inside your home? Not quite endearing.
Nevertheless, even though you might prefer them to stay outdoors, they offer valuable benefits— and their populations are dwindling.
"They're a gardener's greatest ally because they're extremely effective predators," remarks Mary Gardiner, PhD, a professor of entomology at Ohio State University. "While most individuals are aware of the challenges facing bees, many native lady beetles are also under threat due to pesticides, urban development, and competition from non-indigenous species."
In reality, ladybugs aren't even true bugs at all, which is why some experts prefer to call them lady beetles.
"The term 'bug' typically pertains to insects with piercing-sucking mouth parts that may feed on plants," explains Lauren Diepenbrock, an associate professor of entomology at the University of Florida.
Beetles (including ladybugs) possess chewing mouth-parts.

These beetles, though sometimes bothersome indoors, play a crucial role in controlling a wide range of pests that can harm crops and ornamental plants.
"Both native and non-native lady beetles excel at preying upon various soft and vulnerable pests like aphids, scales, mealybugs, and white-flies," explains Diepenbrock.
The diversity among ladybugs extends to various species, presenting a spectrum of colors that may include shades of orange, yellow, and red. Their appearance can vary, with some having distinctive spots, while others lack them. It's important to note that not all ladybug species seek shelter indoors during the winter months.
Here's additional information you should be aware of regarding ladybugs and how to manage them if they enter your home:

Are Ladybugs Harmful?

Lady beetles are generally a minor inconvenience when found indoors. They do not carry diseases or cause damage to wood, as termites do. Ladybugs won't contaminate your food or harm fabrics like pantry or clothes moths. Moreover, they do not reproduce inside your home.
Pets typically don't pay much attention to them because these insects secrete hemolymph, a smelly yellowish fluid resembling blood. Ladybugs release this substance from their joints as a defense mechanism when disturbed, but it's relatively easy to clean up with soap and water.
While lady beetles can bite if they feel threatened, their bite is similar to a pinprick. However, it's worth noting that some individuals may develop allergies to their frass, which is another term for their excrement, as mentioned by Diepenbrock.

Why Do Ladybugs Invade My House?

Adult lady beetles frequently enter homes in search of a sheltered location to spend the winter, as explained by Gardiner. They enter a state of diapause, similar to hibernation, during this period and later emerge in the spring for mating.
Occasionally, they become active on sunny days, which is why you might observe them flying about or perched on your windowsills during a mild mid-winter day.
Nevertheless, not all ladybug species seek winter refuge inside houses. Native ladybugs typically prefer to hibernate outdoors. On the other hand, the most common intruder is the non-native Harmonia axyridis, also known as the multi-colored Asian lady beetle or harlequin beetle.
This particular species naturally winters in light-colored cliffs within its native range, making it particularly drawn to the sunny side of your house, especially if your home has light-colored exteriors. This makes it relatively easy for them to sneak indoors through tiny openings.

Effectively Managing Ladybugs in Your Home

The best approach to preventing Asian lady beetles, or harlequin beetles, from becoming a nuisance indoors is to take proactive measures, as advised by Gardiner.
Lady beetles are remarkably small and can slip through openings as minuscule as 1/8-inch in size. Begin your preparations in late summer before the onset of freezing temperatures, as this is when these insects start seeking refuge for the winter.
While it may be challenging to completely prevent lady beetles from entering your home, these steps can help reduce their numbers:

1. Examine the weatherstripping around windows and doors, sealing any cracks where different materials meet, such as the junction of brick and wood siding, using caulk.
2. Utilize expanding foam to seal crevices around pipes and wires entering your house.
3. Repair any damaged window screens.
4. Install door sweeps or thresholds on exterior doors.
5. Add a rubber seal along the bottom of garage doors.

If lady beetles do find their way indoors, Gardiner suggests a simple solution: vacuum them up. Vacuums do not kill them, so you'll need to dispose of the vacuum bag (as they can escape or create an odor if a large number is collected) or submerge them in soapy water.