Q. Why do ladybugs come into my house? Should I get rid of them?
A. If you find ladybugs in your house, typically between September and November, chances are these are multicolored Asian ladybugs. These Asian ladybugs are native to Asia and in their native range spend the winter hibernating in cracks and crevices of cliff faces. However in Canada, where cliff faces aren’t particularly common, Asian ladybugs have found an alternative spot to overwinter – in and around buildings. They may seek shelter under siding, roof shingles, within soffits, wall cavities, attics, as well as cracks around doorframes and windows.
Rest assured however that these ladybugs are not known to eat building materials, wood, or clothing and are not interested in eating any of our food. In fact, Asian ladybugs do not eat when they overwinter but instead survive off of their body fat stores. They also are not known to carry any human diseases and while they don’t sting they may give you a light bite.
Native ladybugs are one of the good bugs — they help gardeners and farmers by getting rid of insect pests, most notably aphids. While Asian ladybugs also feed on insect pests they can also compete with our native ladybugs for food and habitat.
When ladybugs come en masse inside your house it is understandable if you would prefer them to be outside.
You can try sweeping or vacuuming the ladybugs. It is important to note that they do release a yellowish secretion when disturbed which can be quite smelly and can also stain some surfaces. Some people therefore prefer to vacuum them. If you intend to release them outside place a knee-high nylon stocking into the extension hose or wand of your vacuum, securing it in place with a rubber band, creating somewhat of a bag. When done vacuuming, turn the vacuum off and remove the stocking right away to prevent them from escaping and you can now release them outside. I have been told that if you do not make the “nylon stocking bag” do not leave the lady bugs in the vacuum for too long as you will have an unpleasant smell every time you vacuum.
One source also recommends placing some apple slices where there is ladybug activity. The ladybugs will gather on the slices making it easy to remove them. The apple slices should be replaced every few days.
To prevent further invasions seal any cracks and openings around windows, doors, fascia boards, soffits, pipes and wires with caulking or another appropriate sealant. This is best done in late spring or early summer before ladybugs begin looking for places to overwinter.
Send your wildlife questions to CWF’s conservation researchers, Terri-Lee! Your questions and answers could be featured in a future issue of Wildlife Update!