What is this bug - Ask Extension
This teeny black bug that looks like a mosquito has invaded our home in Portland! I would say they took up residence around mid-December. They are get...
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What is this bug #924439
Asked February 10, 2026, 5:40 PM EST
This teeny black bug that looks like a mosquito has invaded our home in Portland! I would say they took up residence around mid-December. They are getting out of control; they particularly seem to be drawn to the windows though I see them everywhere.
Multnomah County Oregon
Expert Response
Hi,
Thank you for using Ask Extension.
I don't have a sense for the scale of the picture. Are they causing any damage? If they are small, an insect glue strip or other type of sticky trap may be enough to help control them.
You can also use insecticidal soap and spray it on the insects. It is most effective on soft-body insects. I can't tell if the insect has a hard shell (like a lady beetle) that would reduce the effectiveness of insecticidal soap.
Thank you for using Ask Extension.
I don't have a sense for the scale of the picture. Are they causing any damage? If they are small, an insect glue strip or other type of sticky trap may be enough to help control them.
You can also use insecticidal soap and spray it on the insects. It is most effective on soft-body insects. I can't tell if the insect has a hard shell (like a lady beetle) that would reduce the effectiveness of insecticidal soap.
Hi -
These bugs are not causing any damage, and I would estimate them to be maybe 5 mm tops. Best I can tell they are virtually all black with no hard shell. They truly look like tiny mosquitos without a proboscis. They are very easy to clap between your hands to kill them - not dodgy at all.
I’m very much interested in eradicating them, so if you can identify that might help with that project. They seem to be showing no signs of abating!
Thank you.
On Feb 11, 2026, at 12:47 PM, Ask Extension wrote:
On Feb 11, 2026, at 2:59 PM, S. Shattuc wrote:Hi -These bugs are not causing any damage, and I would estimate them to be maybe 5 mm tops. Best I can tell they are virtually all black with no hard shell. They truly look like tiny mosquitos without a proboscis. They are very easy to clap between your hands to kill them - not dodgy at all.I’m very much interested in eradicating them, so if you can identify that might help with that project. They seem to be showing no signs of abating!Thank you.On Feb 11, 2026, at 12:47 PM, Ask Extension wrote:
Hi,
Thank you for sending in the size. I think these are fungus gnats (Bradysia spp.) I found a great article from Colorado extension with options for controls
Fungus Gnats as Houseplant and Indoor Pests | Colorado State University Extension Website
Thank you for sending in the size. I think these are fungus gnats (Bradysia spp.) I found a great article from Colorado extension with options for controls
Fungus Gnats as Houseplant and Indoor Pests | Colorado State University Extension Website
