Posted in  Screening   on  March 6, 2023

What Are No See Ums?

No See Ums, also known as biting midges or sand flies, are tiny, blood-sucking insects that are found in many countries around the world. These biting flies can turn a wonderful summer evening into one filled with painful bites. It is very difficult to kill No See Ums since they are so hard to see. As such, the best way to avoid No See Um bites is to proactively protect your environment.

What Attracts No See Ums?

No See Ums are attracted to moist, muddy, or swampy areas. They also feed on warm-blooded animals, including humans. No See Ums are most active during the night when temperatures drop and humidity rises.

What Causes No See Ums to Bite?

While there isn't a single cause as to why No See Ums bite, some factors may make them more likely to do so. These include body heat, carbon dioxide emissions from the exhaled breath of their targets, how much light is present in their environment, and how close a person is to the area where they live.

No-See-Um Facts: Know Your Enemy

If you are interested in how to get rid of No See Ums, the first thing you need to do is understand them. A few simple steps will go a long way to keep these biting insects controlled.

No See Ums are biting flies, measuring only 1/16th to 1/8th of an inch in size. No See Ums have a lifespan of about 2 weeks to 6 months, depending on the species.

No See Ums feed on warm-blooded animals such as humans, birds, and mammals. No See Ums typically bite around the feet and ankles of their victims, leaving itchy red bumps that can last for days.

5 Ways to Protect from No See Ums

To avoid your property becoming a breeding ground for No See Ums and you from getting bitten, you'll want to review these five steps.

1) Batten Down the Hatches

The first step to No See Um control is to make sure your house is secure from these biting midges. No See Ums can easily enter your house through small cracks and crevices. Checking for tiny openings around windows, doors, and vents can help to keep No See Ums out of your home.

2) Install Special No See Um Mesh Screens

No See Ums are so tiny they can easily pass through standard window screens. As such, if you want to avoid No See Ums, you'll need specialized No See Um mesh screens. No See Um screening is designed with smaller holes to help prevent them from passing through. In addition to screening for doors and windows, No See Um mesh screen is often used for pool enclosures and screened porches.

The technical term for the openings in screens is aperture. Based on Phifer's research of the actual size of No See Ums, an aperture opening of 0.0013 square inches was determined to be the ideal maximum “hole” that would prevent most tiny insects from passing through it. In simple terms, this small opening is achieved by weaving a tighter mesh pattern. It is important to also understand how yarn diameter size factors into making a No See Um screening product. The smaller the yarn diameter, the tighter the mesh must be woven. Conversely, a larger diameter yarn can be used in a more open mesh since the area of the larger yarn will help fill the space of the specified aperture opening.

To learn more about Phifer's leading No See Um mesh screens - CLICK HERE.

3) Try CO2 to Avoid No See Ums

While No See Um screens are the best way to protect from No See Um bites, CO2 traps can help as well. These traps are designed to emit CO2 which attracts No See Ums and trap them before they can enter your outdoor living area. CO2 traps are an ideal way to protect areas you are unable to screen and prevent those unwelcome guests from spoiling your summer fun.

4) Keep Your Yard Dry

To avoid No See Ums, it's important to keep your yard and other areas dry. No See Ums thrive in moist, wet environments and prefer the dampness as a result of high humidity. To combat this, be sure to mow grass regularly, trim trees and bushes, rake leaves and debris that could collect water, and empty standing water sources like buckets or rain barrels. Additionally, make sure to keep all outdoor furniture and items covered if they can't be stored indoors. Doing these things will help ensure your property stays as dry as possible and minimizes the chances of No See Ums setting up a breeding ground on your property.


No See Ums are pesky little flying insects that can be difficult to avoid. By taking the proper precautions, however, you can help ensure No See Ums don't ruin your summer fun. Installing Phifer No See Um mesh screen, setting up CO2 traps in areas that can't be screened, and keeping your yard dry will go a long way to help you and your family enjoy the pool, patio, and other outdoor living areas.

Phifer No-See-Ums Screen - Photo courtesy of 3/8 and Co, LLC

To learn more about Phifer's American Made No See Um screening - CLICK HERE.