Why Ladybugs Swarm on Your House

All of a sudden, on a warm, sunny day, swarms of ladybugs converge on the sunny exterior of your house, garage or shed. Don't you hate it when that happens?

Why They Do It

Ladybugs swarm because they're looking for a warm place to hibernate for winter.

They hibernate in clusters. When one of them finds a suitable place, it releases a pheromone that attracts a couple gazillion more of them. In fact, the pheromone can keep the ladybugs coming back year after year.

Not content to just sit there soakin' up the rays and workin' on their tans, they enter the house in droves. The kids don't have to stand there holding the door open, either.

Ladybugs simply find loose-fitting screens, cracks, and vents, and soon enough, they're house guests. It’s a phenomenon that causes a great deal of exasperation. And they don't even have a name for it!

When and Where It Happens

This phenomenon happens every fall in the eastern U.S. and Canada. In southern New England where I’m from, it occurs on warm, sunny days in October and even into early November.

Ladybugs appear to be most attracted to houses with natural wood siding, houses in wooded areas, light-colored houses warmed in sunlight, and older houses with lots of crevices.

While they are pests, they're not harmful to humans or pets, and they don't reproduce during hibernation or damage structures.

Prevention Is the Best Solution

  • To keep the bugs from getting in, repair loose-fitting windows and doors, seal cracks, and secure vents.
  • If they get in, suck them up with a vacuum cleaner and release them outside, otherwise the survivors can crawl out of the bag and re-infest your house.
  • Their bodily fluids are smelly and can stain, so avoid squishing or sweeping them.
  • If you want to use an insecticide on them, select one that has pyrethrin as the active ingredient. Pyrethrin is a derivative of the chrysanthemum plant and is safer than permethrin, which is highly toxic to cats.

Interesting Facts About Ladybugs

  • Ladybugs are a kind of beetle.
  • Superstition has long held that they are a symbol of good luck and that killing one is bad luck. My hunch is that this superstition has resulted in far more ladybug lives being saved than episodes of good fortune.
  • There are some 400 species of ladybugs in the U.S., and most of them are beneficial.
  • Worldwide, there are over 40,000 different species of beetles.
  • Ladybugs are voracious predators, consuming aphids and other insects that are harmful to plants. That's the silver lining in this cloud of ladybugs. If you have houseplants, it may behoove you to become a ladybug rancher.

Comments 31 comments

Diana Lee profile image

Diana Lee 4 years ago from Potter County, Pa.

We were never bothered much by these invaders until the late 1990s, rumor had it then they had been released here in Pennsylvania to kill gypsy moths or other types of insects harming our trees. Asian beetles will bite you. That in itself is annoying and our trees are still victims of gypsy moths and ash bores. I have found a better way to remove them from window sills in our homes. Duct tape is sticky enough to pluck them right off the surface. They will not lite on a fly sticker and like you said swatting them will leave a nasty residue. I don't like spraying toxic chemicals inside which likely has little effect on them and a vacuum will not kill them it only gives you a way to carry them outside. This is a good topic. Voted up.

Bob Bamberg profile image

Bob Bamberg 4 years ago from Southeastern Massachusetts Author

Hi Diana, nice to have you stop by. God Bless duct tape! Now there are 1002 uses for it. It apparently took a number of years for them to reach your area.

I first became aware of the swarming around '93 or '94. When I was a kid back in the 50's we had ladybugs but I don't remember them swarming in the fall.

I have a niece who lives just northwest of Boston and she called me in a panic one day in the mid 90's. She had come home from work and her kitchen ceiling was plastered with ladybugs. Fortunately, we've only had a few get in the house over the years.

Another cluster hybernator is the boxelder bug and I'll be doing a hub on that soon. I don't have a problem with them, but I know some folks who have.

Thanks for the great comments and the vote. Regards, Bob

Lois 2 years ago

How do you stop them?

Jen 2 years ago

I just leave them be... they do no harm.

Bob Bamberg profile image

Bob Bamberg 2 years ago from Southeastern Massachusetts Author

Hi Lois, the only way to stop them from getting inside your house is to make sure there are no holes in screens, gaps around windows, etc. That's almost impossible to do because most of us aren't aware of those little flaws. You'd just have to do an inspection to find possible entry points. Thanks for stopping by.

You're right, Jen, and if you have houseplants, they'll even eat the aphids, spider mites, and other pests that terrorize them. Nice to have you stop by.

Toni 2 years ago

Is there a difference between the red lady bugs, and the orange Asian lady beetles? We have the orange ones, and I was told by my local garden store clerk that they had no redeeming benefits.

Bob Bamberg profile image

Bob Bamberg 2 years ago from Southeastern Massachusetts Author

There's a difference, biologically, Toni, but to the average person they're no different. I would disagree with the garden store clerk and, in fact, am surprised that he or she said they had no redeeming benefits.

They'll eat aphids, scale, and other soft bodied insects that feed on and damage plants in gardens, ornamental landscaping and crop farms. Glad you stopped by.

Bob Bamberg profile image

Bob Bamberg 2 years ago from Southeastern Massachusetts Author

Hi Nyoma, thanks for stopping by. You're probably getting the box elder bug, which also congregates in large numbers, finds cracks and openings from which to get into your house, and are a real nuisance.

They don't bite or sting, they don't carry diseases, and don't cause major damage to trees, although they can cause deformities in some fruits and the yellowing of leaves. During the spring and summer, they feed on box elder, maple, ash and some fruit trees, .

If they get in your house, their droppings can stain fabrics and some painted surfaces, and if you squash them, they release a pretty awful odor. Like with the lady bugs, it's best to suck them up with a vacuum.

mary615 profile image

mary615 2 years ago from Florida

I had a serious problem with aphids on my Hibiscus plants. Someone told me to get some Ladybugs and where to order them online. I ordered some and turned them loose on the plants. Within two hours all the aphids were gone, and the Ladybugs flew away!!

Great info here, voted UP, etc. and shared.

Jackie Lynnley profile image

Jackie Lynnley 2 years ago from The Beautiful South

I have found lady bugs inside but I just toss them out; would never kill one. They were a favored toy friend in my childhood! I was told way back then they brought luck; so I guess they do!

Bob Bamberg profile image

Bob Bamberg 2 years ago from Southeastern Massachusetts Author

Hi Mary...Lady bugs are voracious predators of aphids, spider mites and other plant pests. Too bad you had to buy them...anyone up here could have mailed you all you wanted! Nice seeing you, thanks for the votes.

Most people I know try not to kill them, either, Jackie. I think the reason is 3-fold: they're harmless unless you're an aphid or other tiny plant pest, their bodily fluids stain if you swat them, and by superstition they're good luck charms. Thanks for stopping by.

Fran Fry 14 months ago

I just had a swarm of Lady bugs, but the swarmed me when I went outside and they kept biting me. I know that sounds weird, but this is the first time I've had this happen. Usually they don't bite, and I didn't think they ever would.

Bob Bamberg profile image

Bob Bamberg 14 months ago from Southeastern Massachusetts Author

That sure is a strange experience, Fran, and I don't know why they'd swarm you. Stranger things have happened, I suppose. I wonder if anyone else out there has had a similar experience? Thanks for stopping by and commenting.

Clowes 13 months ago

I just walked outside with my husband and we were greeted by swarming ladybugs (of some sort) and we had been outside 2 hours prior and they were not there. They were just everywhere and we have never had the problem here before and even when we walked out to our driveway they were floating everywhere and they kept landing on reminded me of the movie "The Birds" only with ladybugs. Ugh!!! We didn't give them a chance to stay on us long enough to bite but my husband has mentioned they bite before because we have had about a dozen in our upstairs before. But absolutely nothing like this!! I don't know anyone who has had this issue here in makes me not want to leave my house but also makes me feel trapped. We have lived in our home for a little over a year and we never had this problem a year ago...sorry but I am all for killing off pests...and in this situation these ladybugs are idea how though at this point, just hoping few get in as I have 4 children.

Bob Bamberg profile image

Bob Bamberg 13 months ago from Southeastern Massachusetts Author

Hi Clowes, nice to meet you. It appears that last year you dodged a bullet but this year you got two in the hat. Any lady bugs that got in will probably show up on ceilings or high on walls to start with. If you swat them, they'll stain the surface. You might consider it a silver lining that they'll hibernate, so won't breed. If you have houseplants, they might be helpful when they wake up in the spring because they eat aphids, spider mites and other small pests that can damage houseplants. Best wishes as you face another Nebraska winter (and we think we have it tough here in New England...ha). Thanks for stopping by and commenting.

Kitty Curry 13 months ago

Got a million of them outside now freaked my 16 yr old son out lol but I told him it was a sign of good luck never seen this many at one time before

Bob Bamberg profile image

Bob Bamberg 13 months ago from Southeastern Massachusetts Author

Hi Kitty, nice to meet you. Your son should be glad they weren't mosquitoes! All I've ever seen were dozens of them on my house, but I've talked with people who said they had hundreds. Luckily not many of them actually make it indoors. Thanks for stopping by and commenting.

Paige 7 weeks ago

OMG I was just taking the dog out and became covered one even in my mouth yech Had to shake them out of my clothes and hair the dog had to be brushed out. I live in a tan house in a wooded area when will it end!!!!

Bob Bamberg profile image

Bob Bamberg 7 weeks ago from Southeastern Massachusetts Author

Hi Paige,

I live in a tan house, too and we've got some unseasonably warm weather coming the next few days...mid 80' I expect to see the swarms, too. It should only last a few days. Thanks for stopping by and commenting.

Rosemary 3 weeks ago

We live in East Texas and yesterday those bugs were all over ...They covered each sunny wall plus our bodies, and a few trying to get into my mouth. We have never seen anything like this swarm. I am still trying to get them out of the house and into our greenhouse, although that may not be a good place for them since everything is hydroponic and I don't think there are any bugs for them to eat. They even got into the dogs coats and then, of course, they brought even more of then into the house. We sure could have used them last spring when every rose bush had aphids.

Bob Bamberg profile image

Bob Bamberg 3 weeks ago from Southeastern Massachusetts Author

Hi Rosemary, they sure are an annoyance, but they're harmless. About the worst thing that can happen is stains on surfaces if you squash them. I don't know if they could survive in the greenhouse if you get below freezing temperatures in East Texas, but food wouldn't be a problem. They gather in swarms to hibernate, and when hibernating, the don't feed. Thanks for commenting.

Joyce 3 weeks ago

They are a nuisance here in northeast Mississippi! I have been spraying them with a mixture of 50/50 peppermint oil and water.

Bob Bamberg profile image

Bob Bamberg 3 weeks ago from Southeastern Massachusetts Author

Hi Joyce, thanks for stopping by. I've not heard of the peppermint oil and water treatment, but it seems a good natural alternative to chemical bug sprays. Does your solution repel or kill the bugs, and are there any surfaces that can be harmed or stained by it?

PamB 2 weeks ago

I'm in Louisiana and just walked outside to let the dogs out....we were swarmed by Asian Ladybugs! Hundreds of them! Flying, landing on the house (stucco) and windows! One did bite my wrist but it didn't really hurt. Have never seen anything like it!

Bob Bamberg profile image

Bob Bamberg 2 weeks ago from Southeastern Massachusetts Author

It's something to see, isn't it, PamB? Stucco would be an excellent surface to attract the lady beetles. You just want to be sure they don't get into your house! Thanks for stopping by and commenting.

Cori 10 days ago

I live in East Texas around Tyler (in a town called Troup) and yesterday I went outside around 3 and they where everywhere!!! My mom even called and said she had like 25 or so in her dining room. I have never seen this !!!! Thanks for the info very helpful!

Angela 10 days ago

Hey. I am in East Texas too in a town called Carthage. I have been seeing a lot of these and today when I got into my car, they were flying around inside. Once I parked, I found several on the outside of my car. From the previous comments, it looks like they are finding East Texas to be a good place right now to swarm. Thanks for the info.

Bob Bamberg profile image

Bob Bamberg 10 days ago from Southeastern Massachusetts Author

Hi Cori, looks like you dodged a bullet til now. You'll probably see them every year, now. I'm glad you found the information useful. Thanks for taking the time to comment.

Bob Bamberg profile image

Bob Bamberg 10 days ago from Southeastern Massachusetts Author

Hi Angela, a lot of folks love East Texas. My step daughter is in Corpus Christi and loves it. The ladybugs aren't particularly fussy...they hibernate in the less attractive areas, too. They're equal opportunity pests! Thanks for stopping by and commenting.

Vanessa Graham 10 days ago

We have had them for the last few days. They're everywhere. We live in Waxahachie, TX/Reagor Springs, Tx. They're all over my house, the brick house across the street & over at my mom's, about 1/2 mi. away. I've never seen anything like this before. What is going on?

Bob Bamberg profile image

Bob Bamberg 10 days ago from Southeastern Massachusetts Author

Hi Vanessa, it looks like they've finally gotten around to your neck of the woods. They're seeking shelter and will try to get into your house. If they do, they'll hibernate, so you won't see them flying around much until Spring. It's best not to swat them because they can stain walls and ceilings. Glad you stopped by...appreciate your comment.

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