BATH — Machinists at Bath Iron Works, Barry Moore and John Crocker were unloading missile-launch assemblies into a guided-missile destroyer when they spotted it. Crocker brushed the spider onto the deck. But Moore noticed it was moving, and he put down a pencil.

“It latched on,” Moore recalls. “I said, ‘This guy’s got an attitude.’ ’’

“This guy” turned out to be a female black widow spider, one of 42 black widows discovered over a two-week period by shipbuilders.

The news was reported Tuesday in Maine, but this story has legs. Picked up by other media outlets, it has been crawling across the country – on the World Wide Web, of course.

Now Moore is explaining for the first time how it all played out.

The day after Thanksgiving, Moore and his co-workers were using a crane to lower missile-launch components into a hold on the USS Michael Murphy, under construction at the Bath yard. Curious, one of the team searched “black widow spider” on his iPhone. Confident of what they had captured, they dropped it into a pill bottle and told their boss.

Black widows don’t live in cold weather climates, such as Maine. They also have a reputation for their venomous bites, and that got the shipyard talking.

The next weekend, workers were uncrating more missile assemblies when they spotted another spider. Then they discovered egg sacks and cobwebs in the crates.

“We found 41 spiders that weekend, and we squished them,” Moore said. “The temperature was in the 20s, but it didn’t seem to affect them.”

The likely explanation, Moore said, is that the crates were shipped from the Seal Beach Naval Weapons Station in California, and the spiders somehow survived Maine’s cold weather.

Reacting to the find, Bath Iron Works hired a pest control company that fumigated the warship’s launcher area, and a warehouse in Brunswick where the crates were stored. No one was bitten, but the news led to a mild case of arachnophobia.

“A lot of our members were concerned,” said Dan Dowling, president of the Local 6 machinist’s union. “We don’t have alligators, rattlesnakes or black widow spiders in Maine.”

Black widow bites can cause dull muscle pain that spreads to the entire body from the bite area, as well as a variety of other symptoms, ranging from light sensitivity to difficulty in breathing, according to the National Institutes of Health. Death in a normally healthy adult is rare, the institute says, but the bite can be fatal for a young child or someone who is elderly or very ill.

BIW also asked a company doctor to meet with workers who might have been  near the spiders. The company wanted to reassure them that healthy adults aren’t at risk of death from these alien arachnids, according to Jim DeMartini, BIW’s spokesman.

The black widow saga has created some offbeat publicity for one of Maine’s largest employers.

DeMartini saw the story briefed in an out-of-state newspaper’s  “strange but true” section. That’s not how he wants to spin it.

“We fumigated,” he said. “And we’re quite confident we followed the right course of action.”