Snakefly Larva In House – What To Do?

Have you spotted a snakefly larva in house and are worried about what harm it can do? We share below all the information you need to know about snakefly larvae.


Most of us would not like a strange insect in our homes. So if you find a black-colored fly with a long neck and netted wings flying around your house, we’re sure you will be concerned!

But there is nothing to be worried about. It is most likely a snakefly that has come in from the outside, and this creature is harmless to you.

While they are rare to see inside the house, snakeflies or snakefly larvae are common insects in gardens and yards.

Here is what you should know about them and how you can get rid of them.

Snakefly Larva In House - What To Do

Are Snakeflies Harmful To Humans?

Snakeflies are not known to pose any kind of threat to humans. Sometimes larval snakeflies might bite us, causing a little bit of skin irritation. However, they are not poisonous, and both larvae and adults usually only feed on insects.

Do they bite or sting?

There are almost no instances of snakeflies biting people. The mouthparts of adult snakefly are forward-facing, and they use them only to feed on aphids and weaker prey. They do not have any kind of stingers on their bodies.

Larval snakeflies have sharper mouthparts at the front. These larvae can bite people, and the bite may leave behind an itchy, painful rash and skin irritation.

However, it is very rare for a snakefly to bite a human. Unless they are threatened, they have no reason to attack you.

Are they poisonous or venomous?

No! Snakeflies are a part of the insect class Raphidioptera, which are insects that mainly feed on wood. They do not contain any kind of poison or venom that affects humans or other animals.

Snakefly Larva In House - What To Do

Do they spread any diseases?

While snakeflies are a common insect that can make their way into your house, they are not known to spread any disease.

Where Do They Live?

Snakeflies are natives of western parts of North America, going as far down as southeastern Mexico and as far up as Canada.

Among all the 206 insect species of snakeflies that scientists have identified, 21 of them live around North America and Canada.

Snakeflies are insects whose habitat is limited to wooded areas. They stay around places with cold temperatures, an estimated 3,000 meters above sea level.

Larval snakeflies live under the bark of trees or the top layer of soil. There are also some species that live in the crevices between rocks.

Snakefly larvae are small insects with segmented bodies which feed on aphids and insect eggs. They have three pairs of legs and are reddish-gray in color.

You can spot these insects in and around your plants, feeding on small aphids and termites.

Female snakeflies lay eggs in small depressions on the surface of a tree’s bark. The larvae overwinter here and feed off whatever is available on the tree.

After they pupate and emerge in warmer climates, the adults move out to search for prey. You can find them in gardens and orchards all through the year.

Snakeflies reproduce only one generation every year, but they can live for around two to three years.

Snakefly Larva In House - What To Do

How Do They Enter Homes?

Snakeflies are typically garden insects that you can find on tree bark and plants. If they have made their way into your home, it is usually by accident.

It is possible that female snakeflies may have laid eggs on windows or plants very close to your house. When these eggs turn into larvae, they might crawl into the house through cracks in the windows, ending up inside your home.

How To Prevent Them From Entering Your House?

While snakeflies or snakefly larvae do not pose any serious threat to humans, you would prefer to keep these insects outside the house. And there are a few ideas you can use to limit snakeflies in the garden:

  • Put up window and door screens to keep the insects from entering the house
  • Try to cover small openings in the window that could be an entrance for the insects
  • You can plug in any ventilation holes around the house to keep the insects away. Using screens on the holes might be a better idea.
  • You could try pest control once in a while if you feel the problem is getting out of hand.

Are They Beneficial?

Snakeflies, whether as larvae or adults, are important beneficial insects in your garden. These insects can be used as biological control of aphids, beetle grubs, and other soft-bodied insects.

Adult snakeflies also feed on eggs and larvae of many different kinds of pests.

Snakefly larvae are effective predators that many gardeners introduce to their plants as pest control. In fact, they are even available for sale at most gardening shops.

Along with ladybugs, beetles, and lacewings, snakeflies can be a good alternative to using pesticides and chemical insecticides on your plants.

Snakefly Larva In House - What To Do

Frequently Asked Questions

What do Snakefly larvae eat?

Snakefly larvae have a varied diet of tree bark and insects. Usually, they feed on wood, insect eggs, and small arthropods.
They can feed on most small soft-bodied insects, including aphids and pear psyllas.

How long do snake flies live?

Snakeflies reproduce seasonally, with one generation born per year. The lifecycle of these insects lasts over two and three years.
They do not have a pupal stage. The insects gestate from a larva to the fly after overwintering in the soil. Most snakeflies will live to around six years.

What kind of bug looks like a snake?

Though they are mostly harmless, snakeflies are insects that look typically like snakes.
They got their names because of their long and slender head, which looks like the hood of a snake. Adult snakeflies also have transparent wings that are longer than their main body.

What did snakefly evolve?

Snakeflies come from a long line of fly species. They are relatives of the dobsonflies and alderflies, which evolved from a species called Mecopteran or Scorpionflies. These flies date back almost 50 million years.

Wrap Up

You do not need to be scared of snakeflies. These are important insects in the ecosystem and are probably good for your garden.

If you run into a problem with them, you can always try to seal cracks in your doors, windows, and window screens to keep them out. 

Overall, these bugs are not going to cause you any problems, so you can simply place them outside your home if you find one or two in the house.

Thank you for reading!

Reader Emails

Snakefly larvae look quite daunting. That’s why many of our readers have sent us emails over the years asking us to identify what this bug is and what they should do about it.

Read on to find out what our readers assumed them to be and some magnificent pics of these larvae.


Letter 1 – Snakefly Larva


Subject: What is this?! Location: Beaverton, OR, USA September 10, 2012 11:44 pm This thing was inching along my computer screen, moving along like a caterpillar or inch worm. When I put something in front of it, it inched backwards. I tried scooping it onto a piece of paper to put outside and it almost spring loaded away, like it jumped. I’ve attached a photo Signature: The bug man?
Snakefly Larva
This sure looks like the larva of a Snakefly, and this image from BugGuide looks even closer than the individual from our archive.  According to BugGuide:  “Both larvae and adults are predatory, though they are capable of catching and killing only small and weak prey. Snakefly larvae feed on eggs and larvae of various insects, as well as adults of minute arthropods (e.g. mites, springtails, barklice, and homopterans).”

Letter 2 – Snakefly Larva


Subject: Couple’s dispute over critter Location: West Linn, Oregon October 6, 2013 9:21 am Greetings, Mr. Bugman, The Boyfriend and I have encountered a few of these fellas trekking across our wooden floor on their way in or out of dark, dry places (underneath mats and such). Every time, the critter has been traveling solo. They are just under an inch long and have dark heads and thoraxes and looooong, pale abdomens. The Boyfriend wants them to be some form of drywood termite, because he admires eusocial critters and is apparently unconcerned about the fate of our 30s-era wooden house. My spidey-sense, however, tells me that it’s a more harmless something else, just coming in to warm up from the recent cold snap. Thanks for your help in settling our heated debate! Signature: Becca
Snakefly Larva
Snakefly Larva
Hi Becca, We are going to side with you on this.  It is a Snakefly Larva, which makes it “a more harmless something else” and not a termite.

Letter 3 – Snakefly Larva


Subject: What is this bug Location: California coast. Santa Cruz October 30, 2013 12:20 am Hi. I recently discovered this little guy inside my home. I have very young children need to know if these are problematic. Signature: Nessa
Snakefly Larva
Snakefly Larva
Hi Nessa, This is a Snakefly Larva and it is harmless.  According to BugGuide:  “Both larvae and adults are predatory, though they are capable of catching and killing only small and weak prey. Snakefly larvae feed on eggs and larvae of various insects, as well as adults of minute arthropods (e.g. mites, springtails, barklice, and homopterans). Adults typically prefer aphids but may eat a wide variety of arthropods.”

Letter 4 – Snakefly Larva


Subject: Little Visitor Location: Sacramento, CA November 9, 2013 6:36 pm Hello, We found this little one in our house the other day. My toddler ”inspected” it and then let it go in the backyard. Any help in identifying it would be most appreciated. I’ve been looking at native species but can’t seem to identify it. It was found in early November in the Northern Sacramento area in California. The one in the photo is about 3/4” long. Sorry the photo isn’t the best. Signature: John
Snakefly Larva
Snakefly Larva
Hi John, This is a harmless, predatory Snakefly larva in the order Raphidioptera.  Adult Snakeflies are rather curious looking insects with long necks that look somewhat prehistoric.

Letter 5 – Snakefly Larva found in bed


Subject: Larvae found in bed Location: Southern Oregon December 10, 2014 6:55 pm This was found on the pillow. Any idea what it might be? Signature: Will
Snakefly Larva
Snakefly Larva
Dear Will, We believe this is a harmless, predatory Snakefly Larva.  See this image on BugGuide for comparison. Thank you!  That would make sense because looking at the link you included, we do have those insects flying around the front door at night.  One must have gotten in the house and completed its lifecycle.

Letter 6 – Snakefly Larva


Subject: What bug is this Location: northern arizona September 7, 2015 2:37 pm Found this guy inside eating small beatles. Looks like a larvae of shine kind, maybe a Dragon fly? Signature: matt
Snakefly Larva
Snakefly Larva
Dear Matt, This is a predatory Snakefly Larva in the order Raphidioptera.  The adult Snakefly is a long necked, winged insect with a weak flight.

Letter 7 – Snakefly Larva


Subject: Centipede baby? Location: Nevada September 25, 2016 4:29 am I found this little guy crawling up my leg I live in Reno NV Signature: Miss mack
Snakefly Larva
Snakefly Larva
Dear Miss Mack, This is the predatory larva of a harmless Snakefly, and this image from BugGuide is a nice comparison.  According to BugGuide:  “Both larvae and adults are predatory, though they are capable of catching and killing only small and weak prey. Snakefly larvae feed on eggs and larvae of various insects, as well as adults of minute arthropods (e.g. mites, springtails, barklice, and homopterans). Adults typically prefer aphids but may eat a wide variety of arthropods. Adults take efforts to clean themselves after feeding.”

Letter 8 – Snakefly Larva


Subject:  what is it? Geographic location of the bug:  Oakland CA, when air quality dangerous due to fire smoke Date: 11/09/2018 Time: 02:21 AM EDT Your letter to the bugman:  We found this in a 2nd story laundry room which is not damp.   It was on a white quilt and appeared to be alone.  it is very very smokey outside due to distant forest fires and we wondered if that may have driven it inside? How you want your letter signed:  pearl
Snakefly Larva
Dear Pearl, This is a Snakefly larva, a harmless predator that is not normally found indoors, though we do not believe the fire was a factor in you finding it indoors.

Letter 9 – Snakefly Larva


Subject:  6-legged-slug-bug Geographic location of the bug:  Davis, CA: basement office Date: 12/04/2018 Time: 04:59 PM EDT Your letter to the bugman:  Hi Bugman, I was sitting at my desk, minding my own business, when this seemingly friendly but very fast moving little guy came cruising towards my arm. He’s looking for something (dinner?) but I don’t know what and I don’t know what he is or where he came from! There are laboratories in this building, but none that do any work on this kinda critter! How you want your letter signed:  Worried about bugs with tails Oh! It’s a snakefly larva 🙂 No further ID necessary!
Snakefly Larva
Dear Worried about bugs with tails. We are pleased that you were able to identify your Snakefly larva without our assistance.

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