Wilkins laughed and said "bats?"
As soon as he had pushed open the door to the Hefley Concourse and light had streamed in, a dark shape seemed to move away and across the high cieling, accompanied by a fluttering rush.
"Or the air conditioning system," said Priscilla, "point your flashlight up there. This looks like the main conduit for the HVAC."
"Of course," said Wilkins, "this is an airport not Carlsbad Caverns. Bats!"
Wilkins shown his flashlight into the depths, where the light seemed to penetrate no more than forty feet before fading into the murk. He reached along the wall, searching for the light switch. "Can't find the switch..." Wilkins shown the light along the wall to reveal a pale female figure standing close enough to touch him. "JESUS!" he shouted, jumping back.
"No", said Priscilla, "Braniff." Wilkins shown the light on the figure, a cardboard stewardess holding a tray full of treats.
Wilkins shown the light on a fluorescent bit of white goo on the stew's cap. Wilkins stepped up for a closer look, and looked Priscilla in the eye. "Looks like...smells like....bat guano."