Whenever I have any pests in the house--insects, rodents, etc.--I call a professional exterminator. Their products are better than anything you can buy in the stores, and they know more than we do about the habits of the pests and how to rid yourself of them.

Moths ??? Pretty sure you do not need hazmat and stop spraying more poison into the air .That is not the proper way to do venting on the roof.

Run the fan 24/7 until you can replace the vent cap. Moths are not going to buck the wind to fly down the vent.

Oh, and make sure there is a backdraft damper at the fan or somewhere in the venting.

Patricia- The hazmat thing was not serious. And we just vacuumed out the dead moths.

I am a bit confused. If they went through that vent wouldn't they end up in the attic crawl space?

I am assuming they are using this cap for a bathroom fan????? So the moths wouldnt have access to the attic. In any case, it is not the proper type venting.

All vent caps should have screens. Does this one have one?

There is no attic or crawl space. There may be a screen, but perhaps the mesh is not small enough to keep moths out. I wish I could go up and look at it, but my husband is afraid I’ll fall off the shed roof. I am fearless, he is not.

What type of moth is it? Are you finding it in your pantry or closet?

Most pantry moths enter the home through infested foods. Their favorite foods include any grain products such as flour, cereal, cornmeal, rice and nuts, but they will also infest birdseed, pet food, dried pasta and dried fruit.

If you see them in the bathroom, it is likely that one entered and laid eggs They will die soon, due to the lack of food, unless they are pantry moths.

run to Home Depot or Lowes, buy a small roll of window screen, cut a piece to fit over the opening and duct tape/glue/rubber band it in place

Thanks for your help! No, they are not pantry moths. They tend to be seasonal here in the tall pines. Everyone has them, but I don’t know of anyone who has a congregation of them in a vent. Thanks again for constructive ideas.