Dear Ann,

Thank you for reaching out to the UVM Extension Master Gardener Program with your question.

Unfortunately I am unable to identify the insect in your photos. I could not see the details of the morphology of the insect in the photo in order to identify the insect. It looked like the antennae are elbowed and the waist is pinched but it is difficult to see in the photos provided. I think that what you are seeing are swarming ants. Ant colonies produce winged swarmers (kings and queens) that fly out to establish new colonies. There are many ant species but only a small number are harmful. Size alone may not be helpful in species identification as there can be variability in size within the same ant species. You stated that the insects in question were about ¼ inch in size but based on the size of the insect compared to the deck board in the photo the insect appears larger. There are details on the body that can help to identify the species of ant that you are seeing. In the photos the wings are obscuring the body.

I presume that your main concern is if you are dealing with carpenter ants. As you probably know carpenter ants like to make their nests in wet wood. As your photo is of a deck and we have had a very wet summer I suspect that there may be some wet wood that could provide a good nesting site so I understand your concern.

I have included collaborators in my response who may provide additional information.

Here are some resources that may be helpful.

Ants | UMN Extension

Ants | CALS (cornell.edu)

E412-Carpenter-ants-around-the-home.pdf (tamu.edu)