The ants were not marching one by one (hurrah, hurrah). They were instead swarming by the thousands.

Last week, I saw crowds of crawling and airborne ants outside of the nature center at Felix Neck. They were clustered on the ground, flying about and creeping en masse up the side of the building.

It wasn’t my first encounter with these winged wonders. Seeing them always gives me pause, thinking that I might have a termite problem, since most folks don’t associate ants with wings and flight.

A quick primer to differentiate flying ants from termites requires a close look at the mass mess. Observe the wings, antenna and body of the little beasts. Ants have dark bodies, bent antennae, a narrow waist and hind wings that are shorter than their front wings. Termites differ in that they have straight antennae, lighter colored plump bodies that have no narrow section and four wings of equal size.

I was not the only one to see this freakish insect phenomenon. Tom Hodgson and Michael Blanchard reported and captured images of ant aggregations, interestingly on Island beaches. Tom shared that it was his “incredibly smart and observant wife,” Christine Gault, who first noticed the ants, finding small numbers at Philbin Beach and at Quansoo, though none were seen at Squibnocket or Lucy Vincent. Michael was at Moshup and other reports corroborated sightings on beaches from Gay Head to Katama.

Tom and Christine’s insects were dead and had washed up on the beach, with the millions appearing as beach rack. Tom surmised that the ants came from colonies in the dunes that emerged for their nuptial flight and, because of their weak flying abilities, tired and fell into the water to be pushed back onto the beach with the southwest winds. Michael’s ants were alive and quite active, crawling on his bag and legs as he flew his drone.

Ant colonies reproduce by swarming. Ants, especially males and queens, will grow wings and emerge from their un derground nests to mate and start new colonies. These swarmers are called alates and that stage is usually a dead-end prospect for the males who die after they mate. Queens, however, will drop or chew off their wings and go below ground to start another colony after their nuptial flights.

Tom also noted that there was an associated scent, a formic acid smell, because that compound’s presence in the ant’s bodies serves as a deterrent to predators. This particular odor — or, more accurately, the detection of it — is similar to that of asparagus as not everyone can smell it. Tom’s nose knows and his comment, “You could live your whole life and never again see this many ants at one time,” captures his enthusiasm for a unique, if smelly, nature moment.

It was difficult to determine what species of ants had put on such a show. Some suggested carpenter ants, though those tend to swarm in the spring. Another possible species was black garden ants that swarm in the fall.

There are many types of ants but Tom’s inquisitive nature caused him to collect a few and provide them to an entomologist for identification. At press time, no definitive species had been confirmed.

Not everyone has Tom’s, Michael’s, or my interest and enthusiasm for such a spectacular spectacle. Felix Neck property staff were quick to act, washing the army of ants off the building with a hose. Commenters on Michael and Tom’s social media posts simply preferred to avoid the beach until the ants were gone, even though they were harmless creatures following their biological imperative to breed. After all, isn’t the Island famous for the popularity of fall nuptials?

Bob Vila had no intention of building these beasts a custom wedding altar or arch. He made clear which camp he fell into concerning the flying stage of ants when he said, “There’s something especially off-putting about an ant that has sprouted wings.”

Suzan Bellincampi is islands director for Felix Neck Wildlife Sanctuary in Edgartown and the Nantucket Wildlife Sanctuaries. She is also the author of Martha’s Vineyard: A Field Guide to Island Nature and The Nature of Martha’s Vineyard.