New research suggests humpback whales use audio cues to help find prey at the bottom of the ocean, but researchers are still not sure how they hunt at night.

The research helps move towards solving a long-standing mystery regarding how these aquatic mammals find dinner when there is almost no light available, Syracuse University reported.

"Humpback whales are known to cooperate with others to corral prey near the surface," said Susan Parks, assistant professor of biology in the College of Arts and Sciences. "Recent studies suggest they may cooperate [with each other], when feeding on bottom prey, as well."

To make their findings, a collaborative multi-institutional consortium of researchers spent a decade looking at the behavior of humpback whales, including their fascinating feeding habits. The team tagged whales with special underwater recording devices, allowing them to listen to how acoustic sound was linked to feeding success.

The team determined humpback whales make a "tick-tock" noise when they are hunting as a group, but are relatively silent when hunting alone. During these feedings the whales most often dined on sand lance (eel-like fish), which bury themselves under the ocean floor.

The findings suggest the vocal sounds are either used to "flush" the sand lance out of hiding so that they can be gobbled up, or serve as a sort of "dinner bell" to tip off other whales.

"Hints of behavior suggest that other whales who overhear the sounds are attracted to them and may eavesdrop on other whales hunting for food," Parks said.

"Prior to joining Syracuse's faculty in 2011, Parks held various appointments at Pennsylvania State University, Cornell University and the Woods Hole Oceanographic Institution. She is the recipient of numerous honors and awards, including the Presidential Early Career Award for Scientists and Engineers, the U.S. government's highest honor for scientists and engineers," Syracuse University noted.

The findings were published in a recent edition of Scientific Reports.