Watch: Massive dragonfly swarms descend on Rhode Island beach

July 31 (UPI) -- Visitors to a Rhode Island beach found their peaceful day interrupted when massive swarms of dragonflies came in from the water.

Beachgoers at Misquamicut Beach in Westerly captured video of the moment when hundreds of thousands of dragonflies suddenly appeared.

Mark Stickney, who posted footage of the swarm to Facebook , told WBZ-TV he "started seeing dragonflies everywhere" right after he arrived at 11 a.m.

Visitors said the dragonflies arrived in waves, with the largest swarm making landfall at about 1 p.m.

Dragonfly expert Ginger Brown said the insects normally migrate between the middle of August and mid-September, but they have been known to travel en masse when their bog and swamp habitats dry up.

"It is entirely possible that's what we're seeing now," Brown said. "They can travel long distances with relative ease."