"I wondered, 'What's the matter?'" Nicholson said. "I'm a helper, so I stopped and said, 'Do you need help?'"
The woman, Justine French of Hershey, said that four ducklings were stuck in the sewer drain while their mother waited nearby with another of her young.
French had been merging onto Route 30 when she spotted the mother duck wandering near the busy road.
"I said to my mother, 'That's an odd place; it's going to get hit,'" French said. "And I knew I wouldn't be able to sleep tonight" if something happened to them.
So, French, Nicholson -- wearing a hooded sweatshirt, flipflops and a skirt -- and Nicholson's husband, Rock, decided to help reunite the family.
The Nicholsons managed to lift the drain grate, but the team needed help from Northern York County Regional Police to gather the four visible ducklings in the area near the open grate. A Northern officer also kept traffic moving at the scene.
"We wouldn't have been able to do it without them," said French, who first dialed 911.
But once those four ducklings were reunited with their mother and the duck family scooted away, the rescuers realized something.
"There were six more (down there)," Nicholson said.
It took another hour for all six remaining ducklings to be rescued, Nicholson said.
And though the self-proclaimed "animal person" has no regrets about rescuing the baby ducks, she's going to be feeling some of after-effects this morning from the mission, she said.
"Apparently, I was elbows-deep in poison ivy," she said. "But I'm just happy to have helped."
The six remaining ducklings are now with Nicholson at her home while she looks for a wildlife rescue or individual to care for them.
Nicholson is already the owner of three rescued pit bulls and a blind Yorkshire Terrier.
"I've always been a big animal fan," she said.
French also has no regrets about her time out in the rain.
"It was a great effort," she said.
How do they get there?
Plenty of ducklings end up in storm drains during the rainy spring months when their mothers lead them across storm grates because the mother's webbed feet are large enough to cross over, but her ducklings' are not, Brian O'Connor of the Animal Rescue League of Boston told the Salem (Mass.) News earlier this month.
On April 12, O'Connor helped rescue about 10 ducklings from a storm drain behind a PetSmart in Danvers, Mass., the paper reported.