PHILADELPHIA (CBS) - Drexel University's annual egg drop contest echoed with a new sound on Monday, giggling, as troops of girl scouts were invited to take part.

This year, 'Introduce a Girl to Engineering Day' coincided with the down-a-slanted-wire drop, says lead event organizer Terri Baker.

"We did have the rules a little different, because they are Girl Scouts," Baker said. "The students here have resources to a little more material that's recyclable."

Gillian, one of the girl scouts from a Media, Pennsylvania group, worked on a project called, 'The Honduran Ghost Bat.'

"It had balloons all around it and it had a tail-like thing," Gillian said describing her group's project.

Troop leader Tracy O'Keefe says a day of engineering was a tough sell for some girls.

"They thought it might be a little nerdy but I think they had fun today," O'Keefe said.

Maybe O'Keefe's a little biased. She is an engineer.

Reported by John Ostapkovich, KYW Newsradio